


Shape of You

by Aythli



Category: Tsubasa: Reservoir Chronicle
Genre: Alternate Universe, Far too much consideration of deep water physics, KuroFai Olympics, M/M, Mermaids, Prompt: Spy, Team Sea, and other deep sea life
Language: English
Status: Completed
Published: 2019-08-21
Updated: 2019-08-21
Packaged: 2020-09-23 11:55:19
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 22,626
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20339704
Author URL: https://archiveofourown.org/users/Aythli/pseuds/Aythli
Summary: No one ever teaches the denizens of the deep to fear the dark. Instead, they learn to fear the surface dwellers and to mistrust the dry and desiccating world they live in. The surface societies continue to explore deeper, but the ocean is a large place. Avoiding them is easy.When his twin is trapped, however, and a surface exploration outpost is implicated, Fai finds himself infiltrating their vessel. Isolated and in a truly alien environment, he can only hope that he remains undiscovered.





	1. Artificial Midnight

**Author's Note:**

> This piece is part of the Kurofai Olympics over at Dreamwidth. I am part of Team Sea and got the prompt ‘Spy.’ If you enjoyed this fix, please go over to the community (kurofai.dreamwidth.org) and score it! Only scores posted to the dreamwidth community will be counted. You’ll also find a number of other fics there for the 2019 Olympics - be sure to check those out too! Massive thanks to the mods for organizing this and to Cloverfield for betaing.

No one ever told him to be afraid of the dark. It was, after all, a very deep ocean, and he had spent the vast majority of his life in the parts that light simply didn't get to. Eons of evolution separated him from his amphibious ancestors, who had lived within spitting distance of the surface and tended to haul themselves out onto land on a regular basis. That evolution had honed him to survive in the dark.

Because it wasn't truly dark - light filtered in, there was just so very little of it. In fits and spurts, his ancestors had moved farther from the surface, farther from the schismed sect that sought dry land instead of the cool embrace of the water. Emboldened by an adventuring spirit that seemed to have faded in recent generations, they travelled to the deeper, darker spaces. Their bodies had adapted.

The world around him was gray and faint but visible. Close at hand, his bioluminescence cast kaleidoscopic rays of color on an enormous and meticulously carved column. Iridescent tiles winked out from among the whorls and knots where cleverly cut shells reflected and dispersed his meager lights. A trail of similarly iridescent paving stones wound away from the column, lit by the reflections.

If he squinted, he could just make out a wall rising in the far gloom. It looked unbroken, uninteresting, but there were three more walls like it, nearly as far away, to either side and behind him. Following a well-marked path seemed as good a place as any to start.

He swept low until his fins nearly brushed the path, not wanting to take a chance of losing it. Occasionally, he would stretch a hand out to brush against the flat-topped, angular stones. He'd never seen anything like them before.

To be fair, he'd never seen anything like this before, either. The Paareyans - his amphibious and long-lost ancestors - didn't build this deep. Or rather, they didn't usually build this deep. He'd found the central column first with his brother weeks ago out of sheer dumb luck, stumbling across it when they'd been hunting. The carvings were unmistakable and had fascinated him.

The architecture, however, was a source of considerable befuddlement for both of them. 

Why was there no roof, they had wondered. In the water, where the predators could and did strike from every conceivable direction, why surround yourself with walls but make the gross oversight of forgetting the roof?

Especially here, at this depth, where the predators were fierce. And strong.

And perpetually hungry.

Maybe they'd all been lunch before they could finish the roof. He smiled humorlessly - a facial expression that his ancestors had never really done away with. His smile, however, had far more teeth than the Paareyans ever had. The predators at this depth were fierce, after all, and sometimes biting back was the best solution.

The wall wasn't nearly as far away as he'd thought. He pulled up short and hung suspended, watching his lights dance across the rough surface, fully aware that flashes and ripples of color occurred because he was softly chattering to himself. "Look at that," he was whispering, though no one was there to see the glowing patterns that his bioluminescence was tracing out in the slowly eddying water. 

The wall, like the path, was a mixture of reflective and matte materials. Unlike the path, which jumbled the two contrasting surfaces haphazardly, this spoke of pain-staking intention. Brightly sparkling shells augmented carved ridges and valleys that swooped over and amongst each other. Each line led to an intricate knot placed dead center within the design. It snared his eye and then his mind and then his heart. 

A deep, omnipresent groan reverberated through the water, shaking him to the core. His head snapped up in time to see the spars of a roof closing over him. He had once, when he was very young, triggered and almost been trapped in a submarine landslide. Tons of sediment and rock roared down, vibrating the water all around with a sound that he felt to the very core of his bones. He'd grabbed his brother's arm and screamed that they needed to move, but the sudden choking sediment rising around them had obscured his lights. His brother hadn't been able to see what he had been saying.

But they'd been level with the very top of it, and the bow wave had thrown them clear.

This time, the displaced water slammed him downwards, tumbling him head over tail. He hit the seafloor, or what he at least thought was the seafloor. It certainly felt softer than the wall, but he had lost all sense of direction.

No one ever told him to be afraid of the dark. He hung suspended in inky blackness, too well balanced to tell up from down. He needed to turn on his lights. He needed to flush the air from his system so that he could either see the bubbles or start to sink.

For several long moments, he was too rattled to do anything other than float until the darkness around him became too oppressive and light screamed to life along the length of his tail, his arms, his back because shouting back at it seemed to be the only thing he was capable of doing.

He was, as it turned out, floating with his back only a few inches from the seafloor. Good. That meant that the way out was ahead of him. He charged upwards, hands outstretched because he had little sense of distance.

His hands collided with something unyielding, giving him just enough warning to slow down. He coiled over himself. His arm, his back, and then the spray of delicate fins that lined the side of his tail glided across the smooth, dark surface. At this distance, he cast brilliant points of light across it. He pressed his hands to it, clawing at the surface, looking for any crack.

But the newly present roof was seamless. The walls were seamless. He circled them quickly, looking for - and failing to find - openings that he could fit through.

He circled them more slowly.

He sank to the bottom, wriggling slightly until the soft sediment partially buried him. The detritus partially obscured his lights, but the comfortable pressure more than offset the slight change to the impenetrable darkness that surrounded him. They would find him. They would move oceans and moons to free him.

He just had to wait.

* * *

He crested the ridge and immediately threw up a hand to shield his eyes. The hulking vessel sat in a relatively flat plane below, looking like an enormous, malformed crustacean. But it was the lights that brought him up short. He hissed and flickered in annoyance, lowering his gaze to let his eyes adjust.

Deep ocean sediment had started to drift over the broad, circular feet that held up the main body. Jointed mechanical legs rose from the feet to disappear under the squat, round column of metal and glass that sat in the center of the station. Each leg extended to a slightly different length in a clear effort to level the structure despite the uneven seafloor. The column was a patchwork of polished metal sheeting and curved observation windows, and he could make out several individual floors within it. Boxes, tables, cabinets - each floor was crowded with detritus of unknown use. Tunnels radiated from it, joining to other squat cylindrical structures in places, ending in convex glass in others.

At the lowest level of the central structure, he could just make out a figure moving amongst the tables. It stuck to the outside, circling the perimeter slowly and periodically pausing.

Every inch of the structure was crowned with lights that pointed out and down. One illuminated a name painted down the side of the hub. He tipped his head to read it - "Ika." The letters felt odd in his mind, ever so slightly off-kilter from the script that he grew up with. The rest of the lights pierced the surrounding darkness, casting shadows across the isolated rocky outcrops, the swales of deep water sediment, and the radial tunnels. Schools of small fish darted in and out. In the shadows, their own vibrant bioluminescence was visible - large eye-like structures and angular markings meant to mimic the very predators that hunted them - but under the lights, their colors were reduced to muted, albeit reflective, grays and browns.

Ashura caught his arm, pulling his attention away from the tableau. "It is time."

"Where do we go?"

"Down." Ashura pointed to the central hub. "Below it. Do you see the water?"

He squinted. Through the windows, he could just make out a large circular opening in the floor. "An open door?"

“A deep harbor, where they launch their machines.”

“He keeps turning his back to the water. Foolishness or arrogance?” 

“Faith.”

He tipped his head slowly to one side, the gesture conveying the question.

“Belief that he is the only thing down here that can survive the dry air.”

The assumption was not asinine. Two days ago - two  _ hours _ ago - he would have drawn the same conclusion. Conversion from water- to air-breathing or vice versa was a genetic miracle that had died with the Paareyans. Even as a Mimic, with a multitude of forms available at his fingertips, he couldn’t simply trade his gills for lungs. Molding of his outer form was easy, but he couldn’t remake his organs.

But the spell that Ashura uncovered was purported to accomplish what the Paareyans had done naturally. It was untested, possibly deadly and almost certainly unstable. Casting it could easily render him incapable of breathing either water or air.

He didn’t care.

The long-term effects didn't matter, of course, what mattered was finding what had triggered the failsafe that imprisoned his brother. That's why he was here. He was willing to do anything in the hopes of making progress because the alternative was agonizing over his brother. The alternative was picturing him floating alone in the silent dark.

The alternative was slamming himself against the doors until either he or the stones that blocked his way shattered.

He clung to the shadows below the radiating tunnels where the bright lights couldn't reach him. With the contrast and with his bioluminescence as low as he could possibly make it, he was little more than a finned shadow, easily passed off as any of the large fish that hunted this depth.

From underneath, the deep harbor formed an annulus of distorted lights and shadows. Metal pipes encircled it - bumpers to cushion the machines or handholds to help the air-breathers climb from the water, he didn’t know and didn’t particularly care. He caught hold of one with a long-fingered hand, holding himself steady against the slight current. A few quick kicks, and the drifts of sediment swirled into the water column until the whipcoil of his tail and the lights within were almost completely obscured. A few minutes more and the bioluminescence speckled across his face and arms was blocked as well. Even if the person within chanced to look down, he would see nothing. 

Under the cover of suspended sediment, a complicated string of symbols fell from his fingers in a glowing blue fire that refused to be extinguished by the surrounding water. They settled slowly to the ocean floor, scalding into the sand. The water within the ring twisted, roiled, and blew upwards through the center of the annulus. Crashes of unsecured crates, tools, and machines and a deeper, softer impact vibrated through the water column.

A smile. A brief flicker of teeth that had long since forgotten genetic ties to any herbivorous ancestors.

Ashura grabbed his wrist, spinning him around bodily with the force engendered to a creature nearly twice his size. Lights spun past his face, the words there and then gone almost faster than he could process them. “Change, now,” Ashura ordered.

He changed.

As a Mimic, impersonating his fellow sea creatures was easy, but his fellow sea creatures tended to fall into the same mold. As younglings, they’d played as multi-limbed crustaceans, but never for very long. Twisting your bones and pouring your body into a shape so alien was uncomfortable at best and excruciating at worst.

Splitting his tail almost undid him. The symmetry line that ran between his lateral fins and down to his flukes was a natural divisor, but he didn’t have a mirrored skeletal structure beneath it. He had to reshape his bones instead, lengthening and thinning, borrowing from vertebrae that had little to spare.

He was dimly aware that he was screaming. Then Ashura’s hand, full of burning magic, came down on his back, and he was intensely aware that he was screaming.

The sound cut off. The latent seawater in his respiratory system was sitting in lungs that no longer functioned underwater. It burned horribly. He heaved, chest spasming in an effort to expel the water even though he had nothing to replace it with. Desperate need for air clawed at him, but he clamped his mouth shut to keep from inhaling more seawater.

He had to get up and into the habitat - the only option for survival now. Without fins to drive him, however, the deck seemed impossibly far up. Disjointed kicking of his newly formed legs did little to lift him. He could, theoretically, still adjust his buoyancy, but he couldn’t think past the screaming of his starved lungs.

Ashura’s hands gripped his legs, finding support under joints that he hadn’t had a minute ago and shoving him towards the surface.

The decking rose up to meet him.

* * *

_ “Although few records are preserved documenting the cataclysm that schismed Paareyan society, we know that only the surface and deep populations survived. If the borderlands that occupy the shallows were not completely evacuated (see Section 4.2.5 for further analysis), there is no evidence that anyone remaining lived. Standard radiometric dating techniques suggest that the borderlands remained uninhabited for nearly three centuries before colonists returned. _

_ Paareyan exploration of the deep reaches becomes, for lack of a better word, more frantic towards the last century of their existence - an observation that raises the question as to whether they knew that the Bloom was coming and were looking for safe harbor. _

_ The power station structures across the Boiling Sands conflict with suggestions that the Paareyans were simply exploring. Ocean-bottom mapping of the power lines that radiate from them is currently insufficient, but what images we do have show hardened cables surrounded by interlocking stone conduits. We have traced these conduits to some of the ruins at the same approximate depth as the Boiling Sands, but at least three go deeper than we are currently able to explore. Given location and direction, we believe that at least one connects to proposed ruins identified using low resolution sonar in the Ifirge. Given both the depth and permanence of these preserved structures, we argue that the Paareyans were establishing a permanent foothold that formed the basis for today’s deep societies.” _

_ \- Excerpt from quarterly research report, Syaoran Li, Lead Archaeologist, Fathom Exploration _

_ “Ika Station deployed; systems nominal. No data yet on these structures, but the power in them is still on. I’ll have more to send once the storm passes.” _

_ \- Archived transmission, Kurogane, Chief Engineer, Fathom Exploration _

* * *

The air was blissful. He sucked in a breath, rolled onto his side, and coughed up the last of the water. The station's inhabitant was sprawled on the floor only a few feet away. He lurched up onto his elbows and dragged himself over, not trusting his shaky legs and not trusting his mind to work them properly. He had to get the spell in place before the other woke up, and sprawling across him wasn't going to help.

His hands were still wet from the sea, and he channelled power into the veneer. Blue light poured down his arms to gather at his fingertips. A chaotic jumble of angular symbols criss-crossed his palms and licked up the lengths of his fingers to the bright points at the tips. He stretched over the unconscious body to grip both wrists. Each individual flame peeled from his skin and tacked onto the other's. Once they had all transferred, he took his hands slowly away and watched the blue fire sink below the skin and fade to an inky black.

The spell was generic and simple because any fact that directly interfered with it could break it. He simply didn't know enough about the station, the mission, or the target to make it specific. So it twisted memories, inserted him in the background wherever it could, and would directly alter any recollections as plausibly as possible. 

But it wouldn't cover egregious stupidity.

It wouldn't, for example, explain away his nudity or the fact that he'd suddenly forgotten his companion's name unless he did some fast talking. Considering his grasp of the surface dialect was shaky at best and rudimentary at worst, fast talking was not likely to get him out of a bind. 

Which meant he needed to find some clothes and information. He channeled a bit more power and added a mark to the back of his neck, just below his hairline. Even though the enchantment he’d placed on the other person would allow them to understand him, he still needed to be able to understand their language. He spoke a bit and could read hesitantly since their alphabets shared a common source. The spell he placed on himself would boost his existing comprehension, driving his brain to process faster so that his understanding wouldn’t lag.

Walking proved to be every bit as difficult as it looked. He hauled himself up on one of the crates that dotted the deck around the deep harbor and staggered from desk to crate to the wall. With one hand braced on the curved metal sheeting to keep himself upright, he pawed at the recessed handles until a door popped open.

Their two civilizations shared a common ancestry, after all, and they hadn't diverged that much in the intervening millennia. A closet was still a closet. Spare dry clothes seemed an unavoidable precaution this close to open water. As there wasn't a railing around the deep harbor, falling in seemed ludicrously easy.

He fished out a shirt and a pair of pants that matched those worn by the person still sprawled on the floor. A uniform? Possibly. Hopefully. Explaining why he was borrowing someone else's clothes was not high on his priority list. He pulled them on, fighting with the pants for several long minutes before giving up and sitting down. He had to roll the ends up to keep them out from under his feet, and the sleeveless shirt he yanked over his head hung loose around his frame.

Given the size of the clothes, borrowing shoes would have almost certainly been out of the question even if there had been any spares. A hoarse groan from behind him reminded him that he was not alone and that he couldn't spare the time to go hunting for shoes. He stumbled to a wall-mounted terminal and pressed a hand to the glass screen cover to bring the computer to life. His fingers spread uncomfortably far. After a moment of staring, he realized it was caused by the lack of webbing that normally connected his fingers to the second knuckle. Staring at the disconnected appendages made his stomach flip, and he tore his eyes away.

The computer was hard to navigate. This kind of digital technology simply didn't exist in the deep - electricity and water weren't the best bedfellows - and he only had the most rudimentary knowledge courtesy of the books that Ashura had obtained in the Borderlands. He clicked on random icons, hoping that interlocks would prevent him from doing something stupid like venting the station. The mission description and crew manifest, such as it was, popped up after the third attempt.

The mission title read:  _ prototype deployment and preparation for further crew occupation. _ Against all odds, he'd infiltrated a solo mission and wouldn't have to skulk around to ambush and enchant the rest of the crew. He panned to the crew manifest, just catching a glimpse of a name before a hand came down heavy on his shoulder.

"What...," a long pause. The hand's owner shook his head and then prodded gingerly at a large lump forming on his temple, just at the edge of his hairline. His black hair was shoved back from his face and did little to hide the injury. "What happened?"

He plastered what he hoped was a bright smile on his face - without the needle-like teeth, his smile was more disarming than threatening. "Welcome back, Kuro. How's your head?"

"I told you. It's Kurogane." Another shake of his head. Kurogane seemed to be staring at the floor intently. "And I also told you to put on shoes."

"Oh, you know me. I never cared for footwear." A lie. They'd never had that conversation - they'd never had any conversation before this one - but the spell would loop it into Kurogane's memories as a built-in excuse for his strange appearance. The wholly spoken language felt strange in Fai's mouth. He'd practiced with his brother and Ashura, but none of them had been able to suppress the bioluminescent commentary completely. Sound alone seemed insufficient to convey the nuances he would normally have used, but he pressed on.

"It's not safe...." Kurogane frowned at him. 

"Fai," he supplied, after a half a second's hesitation. Not his name, not really, but close enough to the truth that he would answer to it.

"Fai." He leaned heavily on the shelf beside the console and shook his head again.

"I think you may have hit your head harder than you thought, Kuro." Fai looped an arm around Kurogane's waist, more to support himself than the other way around. He still didn't trust his legs. "Let's get you patched up."

"I  _ told  _ you."

"It's Kurogane, yes. But have I ever called you that?"he started the, moving in what he hoped was the correct direction. "Why should I start now?"

"If you're going to be obnoxious again, at least take the short way to the infirmary."

_ Again? _ He wondered what memories the spell was conjuring up to explain his presence. "I thought I was," he said in what he hoped was a blithe tone.

Kurogane leaned heavily on him - a motion that would have made both of them collapse except that Fai's legs had apparently decided that, since there were two of them, there was no point in standing with his feet close together. He managed to brace himself, surprised by the size difference.

In all honesty, he'd guessed at an acceptable body build. Even as a Mimic - one of the smaller deep races - he was still several times the length of a surface dweller in his natural form. Ashura, who towered above Fai by several unfair multiples, would have dwarfed this man. So Fai had shrunk when he changed, partially because he'd borrowed bone from his spine to form his hips and legs, and partially because he had some vague knowledge of the scaling proportions amongst the different societies. He had completely guessed at the magnitude.

He was shorter than Kurogane by a fair amount, but given the height of the cabinets and desks, he'd be willing to bet that Kurogane was taller than average. The difference between their girths was the more shocking comparison. In his true form, Fai's body tapered down from its widest point at his shoulders. The transition from ribcage to heavily muscled tail happened seamlessly. He didn't normally have hips.

To be brutally fair, he did not appear to have much in the way of hips in this form, either. He'd guessed and, judging from his companion, had grossly underestimated. He looked fragile in comparison. Thankfully, the spell would smooth over all oddities of his appearance. When you saw someone routinely, strange proportions simply faded into the background.

"The infirmary is out that door." Kurogane pointed with his free arm at one of the glass-panelled spokes that stretched out from the central room they were standing in. "Unless you were planning on swimming, you're going the long way around the deep harbor to get to it."

"Maybe the longer walk is part of the treatment."

"Fine. I'm not going to argue with the medic."

"An excellent decision." Fai  _ had _ suggested that they get Kurogane patched up, after all. It wasn't a particularly enormous logical leap, especially with the spell frantically trying to slot Fai into any plausible space in Kurogane's memories. The best he could do was not contradict the assumptions.

They took the long way around. Fai's muscles were strong even if they weren't used to bipedal motion, and he'd backed himself into a corner by insisting that it was part of the treatment.

Kurogane stumbled over the decking and snarled in pain, pressing one hand to his head. "I've never seen anything like that. Could it have been caused by the storm?"

"I don't see much of a storm out there."

"Not weather. The solar storm. The one that's cut off our comms." Kurogane scoffed under his breath. "Tomoyo would know."

"Too bad we can't ask her."

"The cause isn't that important. Just stay away from the deep harbor until the comms come back up." Another noise of derision, and then he said, "Comms have been down for less than three hours. I thought I'd make it longer before feeling like I needed to call home."

"Well, at least we have each other. Right, Kuro?"

Kurogane glared, and he smiled. The easy banter continued, just like they had known each other all their lives.


	2. Shadows in the Water

This deep under the water, diurnal schedules were little more than a nod to normality. Fai had almost forgotten about that aspect of the surface societies until the intensely bright lights that edged the tops of the corridors and the margins of the rooms slowly dimmed. For a moment, he feared that he'd inaccurately reshaped his eyes, but then the lights settled on a low illumination and soft red lighting came up along the edges of the floorboards.

Night time. How did the surface dwellers survive on this kind of schedule? He couldn't imagine being comatose and vulnerable for hours on end.

Kurogane reached out and plucked the ice pack from his hands, reminding him that he wasn't supposed to be marveling at the dichotomies of their respective cultures. “What’s wrong?”

“I didn't realize how late it was."

"You should get some sleep."

"I thought that was my line."

"I thought sleeping after a concussion was inadvisable."

Fai forced a smile onto his face. He didn't sleep for more than a handful of minutes at at time - none of the deep dwellers did. Concussions happened - he'd seen people struck by debris, seen them injured during territorial battles and in attacks from the deep predators - but sleep simply wasn’t a concern. He bit back the question about what, exactly, happened if you mixed sleep and concussions.

Since the spell had apparently assigned him the role of medic, he probably should refrain from quizzing Kurogane about presumably wide-spread surficial medical practices. Instead, he leaned against the cushioned table. Staying still for an extended period of time was proving difficult. He was too used to drifting. “Need help staying awake?”

Kurogane snorted, as if reacting to an often-rehashed joke between them. “I have work to do.”

* * *

_ “The Boiling Sands, so named by the Paareyans for the geothermally-heated water that circulates in the shallow subsurface, represented a key energy reserve for their deep water exploration activities. The power stations have been unmanaged for centuries, but appear to still be generating power. We cannot analyze power transmission through the conduits from here, and so we do not know whether this energy is still being used to power deeper Paareyan infrastructure. Although some of our resource managers have suggested that we utilize the existing infrastructure to power our bases, I will not authorize that option until we are sure that unplugging the current conduits will not shut off something important. Please reconcile yourself to this decision and do not propose it again without further data of current Paareyan power usage.” _

_ \- Excerpt from interdepartmental communications, Tomoyo Daidouji, President, Fathom Exploration _

_ “I’ve transferred the updated programs to the sea spiders. New coding should fix the problems we had with the legs acting independently from one another. No more picking up all their legs at once :) They should be ready to explore the power conduits. I can’t wait to see what you find!” _

_ \- Archived memorandum, Sakura Kinomoto to Kurogane, Engineering Group of Fathom Exploration _

_ “I’ll send the sea spiders out after the storm.” _

_ \- Archived memorandum, Kurogane to Sakura Kinomoto, Engineering Group of Fathom Exploration _

_ “Stop with the smiley faces.” _

_ \- Archived memorandum, Kurogane to Sakura Kinomoto, Engineering Group of Fathom Exploration _

* * *

After a few minutes of fumbling with likely looking panels, Fai managed to uncover a computer terminal. With Kurogane out of the room, he had a moment to gather information and space to breathe.

Gods below, his gills hurt. He didn’t need them, of course. With the changes wrought to his internal organs, he was breathing the air comfortably, but his gills were stationary for the first time in his life. They _ ached._

The sleeveless shirt he’d pulled on hung loose around his shoulders. His gills weren’t moving but were they still there? Almost all the panels around the room concealed storage compartments, and - after tearing most of them open - he finally found one panel that opened on a mirror mounted on a collapsible arm. The back of the panel was also reflective, and, after a moment of frowning at the set-up, Fai realized that it was probably there in case the medic had to patch themselves up. Certainly a less-than-appealing option, but it suited his purposes. He yanked the articulated mirror out, positioning it until he could see his back. 

His gills were simply gone. In their place, Ashura’s magic had left an intricate black tattoo that spanned his entire back, wrapped over his shoulder, and curled around his ribs. The edges of it stuck out from under his shirt, visible but presumably nondescript to Kurogane’s enchanted eyes.

He breathed. His chest rose and fell. His back remained smooth and unbroken. 

He swallowed bile and yanked his gaze up and away to meet his reflection’s eyes.

His face shouldn’t have caused as much shock as his absent gills. The surface and deep dwellers shared a common heritage, after all, and their facial structures hadn’t changed much in the ensuing generations. Those that lived on the surface had a wider variety of colorations - Fai’s people poured their color into their bioluminescence, and his current form had carried over the pale skin and light hair.

His eyes, however. Without the lights that typically dotted his arms and tail, his skin looked wan. In compensation, the lost color had poured into his eyes. Instead of their typical, lid-to-lid deep black, his eyes were a crystal blue so bright that they could have been lit from within. He winced, wondering how much of that was a redirection of his light, and tried, to no avail, to tone it down. At least Kurogane's eyes were nearly as bright in color, albeit an odd shade of red instead.

The change to his visage was almost as shocking as the lack of gills and the fact that, when he looked down, he still had legs instead of a tail. Despite the same narrow face, he didn’t look like himself anymore - he didn’t look like his _ twin _ anymore, and for a moment, that thought twisted tight within him, as if his changed exterior foretold his brother’s demise.

With a muttered curse that didn’t carry nearly the weight he wanted without the addition of his lights, he shoved the mirrors away and turned back to the terminal he’d abandoned. He tapped on the screen until it brightened. Navigating was easier than it had been in the deep harbor. The screen there had been cluttered with icons for easy access, although he had no idea what exactly Kurogane needed to access easily. This computer looked unused, uncustomized to the medic who would eventually be occupying this sick bay. Good. That meant that he wouldn’t have to mimic the idiosyncrasies of a real person. He was filling in a blank space in Kurogane’s mind.

It also meant that he could easily navigate to the current records.

He considered adding a crew record for himself, but almost immediately thought better of it. The enchantment would slide any suspicious thoughts away. It wouldn’t even occur to Kurogane to check the crew roster for him, and, not knowing the intricacies of the documentation, he was more likely to raise suspicions by fumbling around creating records in the computer.

It would also leave a trail that he had been here, but he wouldn’t be able to erase Kurogane’s memories, so there was little he could do to mask his presence.

He finally located the mission documents, scanning them quickly. The Boiling Sands seemed to be the main target of the exploration from a whole slew of engineering and archaeological pursuits, but the current status was as he had surmised in the deep harbor - set-up and deployment.

The deep societies had also been interested in acquiring the resources of the Boiling Sands, but the edges brushed too close to the Borderlands. Too shallow, too proximal to the other societies, the deep had left them alone.

Conduits radiated from the squat rectangular power stations that dotted the Boiling Sands. Orienting himself with respect to the Ika, the seafloor topography, and the Paareyan structure where he’d lost his brother took a minute, but at least one power conduit ran towards the structure in question. If he projected the path, the connection from the power station to the structures his brother had been exploring seemed ludicrously easy to draw.

It should have been abandoned and little more than ruins. His brother had _ assured _ him of that. But it was powered.

He could almost hear the echo of Kyle’s voice, shouting to be heard over the council, Ashura, and himself. The insistence that his brother’s entrapment was an act of war had stuck in the back of his mind. The conjecture had seemed absurd at the time, but he had been willing to let the fears play through the council’s mind if it meant placing him somewhere where he could do something - _ anything _ \- to help his brother. With the Ika representing the deepest toehold of the surface societies, it was the easiest access they had.

Had Kyle known about connection between the Ika, the Boiling Sands, and Ifirge...? Fai shuddered to think of it. He did not buy into the warmongering, but an accident seemed perfectly reasonable.

Especially when the next set of documents contained references to mechanical exploration drones labeled as ‘sea spiders,’ proposals to splice power lines and borrow energy, and explore the deeper connections that no doubt referred to the conduits that led to Ifirge. Could a cut power line have triggered the doors to close? He opened file after file, trying to determine when the sea spiders had been launched. A memo from Kurogane to someone on the surface vessel mentioned waiting until after a storm.

The _ storm... _Kurogane had mentioned something about a storm disrupting communications. It took him too long to find the storm predictions and even longer to find a diurnal calendar that told him the date according to the surface societies. He stared.

_ Weeks _ left to go. The storm had started only a few hours before he’d arrived. Nothing in the files indicated that the Ika - or any of its assorted machines - had interfered with the Paareyan technology on the Boiling Sands. 

* * *

Water, even this deep, was rarely still. Sinking cold and rising hot water spawned massive convection cells that drove the shallow and deep currents. The endless recycling oxygenated the depths, made it liveable, and brought new food sources to those desperate for novel tastes.

This ancient structure was fully enclosed, however. He hung limp in the darkness, floating in perfect suspension. After the roof had closed, the cavitations had roiled through the water for hours, their intensity shrinking with each reverberation off the walls until the water had stilled. His occasional motions stirred it slightly, but the room was too big for his movements to matter.

The stillness was unnerving and was having an unexpected impact on his biology. The lack of circulation was dangerous - without reintroduction of oxygen, he could suffocate. In an enclosure so much bigger than himself, it would take months for that occur, but his body couldn’t know that. To his body, the stillness was a threat. In response, his circadian rhythms were slowing until he was entering a kind of stasis. His brain felt sluggish, his muscles limp. He had no idea how long he’d been trapped.

He could hear motion and voices on the other side of the roof. Enough people had gathered that the echoes against the stone were getting through. But without seeing them, and with his mind fogged by his partial hibernation, it was as if he could only hear partial words in an incomplete conversation. He could not reconstruct it.

A swell of water swept past him, lifting him and then pressing him back down as it reflected off the roof. The roof remained closed and the walls intact. The suffocating darkness was too complete to permit anything else. With the motion of the water came the return of his intellect. His thoughts crystallized.

The water buffeted him. Somewhere in the darkness, he heard the susurration of water over scales. 

He was not alone.

* * *

The glass paneling was cool to the touch. In the dim overnight lights, if he rested his head against it, he could block most of the reflections. With the cool surface on his forehead, he could almost convince himself that he was touching the water beyond. He could almost convince himself that he could feel the comforting swirl of the currents that were spiraling small plankton past the flood lights outside.

The reflections that he couldn't quite block with his body shifted. He jerked his head away from the glass, guilty at being caught for no discernable reason.

"You should sleep."

"Thanks for worrying, Kuro, but I'll get some sleep later. I'm not tired." _ That _ was a blatant lie. Fai normally slept for a few minutes at a time throughout an entire day, a habit that he simply couldn't maintain on the Ika for a range of reasons starting at paranoia and ending at feasibility. Bipedal constructs weren't made to sleep upright, and Fai had yet to find unused but functional sleeping quarters. Since Kurogane was deploying the Ika and preparing it for full missions, only having one currently functional bed made a certain amount of sense, but it was making his life particularly difficult.

Little more than twenty-four hours had passed since he’d infiltrated the Ika, and he was exhausted. 

Kurogane blew a breath out through his nose, an affectation that didn't exist in the deep societies but conveyed his exasperation clearly nevertheless. "You _ need _ to sleep. Come in soon." He leaned down quickly and then stopped, his lips a hair's breadth from Fai's cheek.

Unlike the myriad of irritated noises that only the airbreathing descendants had inherited from the Paareyans, both cultures incorporated kissing as a sign of affection. Fai knew this. It was one of those basic cultural facts that even the insular deep societies saw fit to teach their children about - although the lessons came hand-in-hand with stories meant to highlight the dangers of mingling with the surface dwellers that contained horrid details from the borderlands. He knew this as some disconnected fact that could be impartially examined and trotted out at social gatherings for the interest of those around him.

In all honesty, he had never expected to get an object lesson in their similarities.

He barely breathed, wondering if Kurogane would continue his trajectory, wondering what had spawned this, wondering if it had been some mental slip caused by the concussion the previous day that they would laugh about later. "Kuro...?"

"It's Kurogane." He hadn't moved any closer, but he also hadn't moved any farther away. They hung for several long moments, suspended within scarce inches of each other. "You should sleep," Kurogane reiterated finally and leaned back with a clear force of will before turning to walk back down the corridor to his sleeping quarters.

Even resting his face against the cool glass of the corridor wasn’t enough to cool the heat that burned across his cheek from Kurogane’s breath. 

This was too dangerous for too little gain. He’d spent the previous night scouring the Ika’s databanks for any connection to his brother’s imprisonment but continuously turned up nothing. His presence here was useless, frittering away time while his brother was trapped.

Every second he stayed, he risked Kurogane discovering him and risked falling into the clutches of the surface societies. The whispers that circulated about the surface societies and their need to conquer the deep carried promises of exploitation and pain to anyone of the deep that they managed to capture. 

He turned and ran for the deep harbor.

* * *

_ “The deep Paareyan exploration is also of particular religious interest because of their previous hesitancy to breach the realm of the gods. A full summary of the Paareyan religious system is not appropriate here, but our belief systems draw heavily from Paareyan traditions. Like our systems, the Paareyans worshipped the deep gods - the predators of the deepest oceans that are reported to have measured tens of meters in length. These giants were at the top - or, more accurately, the bottom - of the global food chain. Water runs downhill, after all, and so everything from the highest mountain on down helped to feed these creatures. Most surface societies, the borderlands, and presumably the deep societies continue to venerate these apex predators, although the typical assumption is that they did not survive the Bloom. Loss of food sources in the shallows would have significant effects on the survival of deep species and especially on these enormous, exclusively deep predators. _

_ I believe.... Some Paareyan reports... Some translations from the Paareyan surface ruins seem to indicate that the deep exploration may have been to find the deep gods. I think that they might have been attempting to save them from the Bloom, but I have no idea how they could do it. Fossils...we know they existed once, did they go extinct before the Bloom? After? Are they still around? The Paareyans couldn’t exactly bring them onto land to survive, maybe that’s why they started colonies in the deep? I don’t think I can tell from the data I have.” _

_ \- Archived draft report, Syaoran Li, Lead Archaeologist, Fathom Exploration _

* * *

With the dim lights in the deep harbor and the intense illumination of the seafloor outside, Fai could see through the surface of the water. Small schools of fish darted past the opening. His gills ached. His legs shuddered with the need to merge and scale over. He fell to his knees, clawing at the loose shirt covering the spell that sealed his gills.

Water. He needed water for his magic. He fell forward onto his stomach and pressed his hands into the water. Rivulets oozed up his forearms, drawn almost magnetically to the power within him that made him a Mimic. His magic poured downwards in response to the rising water. Cold flames that might have been waves and might have been fins licked down his arms following the path where his fins should have been. The magic gathered in his palms, merging and illuminating the water.

The tattoo across his shoulders burned. Each arched symbol woke at the presence of his magic, and he could feel the pinpoints of fire that marked the control points of the spell. They were....

Gods below, Ashura had placed the control points between his shoulder blades. He contorted across the decking, desperately trying to reach the spots that would allow him to release the spell. His arms refused to bend far enough.

Frustration burned through him for one horrifyingly stupid moment before he remembered himself. As a Mimic, his proportions where wholly his to control. He stretched his arms and reversed his joints, pressing his face into the deck to muffle his pained groans. His fingers lengthened to impossible dimensions. The individual digits looked spidery and frail, but they reached the control points of Ashura’s spell.

Water infused with his magic crystallized between his fingers and the control points, sharp spines that burned with internal fire emerging from his shoulder blades. The intricate tangles of the spell snarled his magic, twisting his mind around and befuddling his attempts to remove it. Every loop that he managed to unknot coiled around to ensnare another portion of his body. He hissed and continued to dump power into the spell. If he could only find one end of the spell, he’d be able to untangle it.

But the magic remained stubbornly knotted around his body. Ashura was immensely older and more experienced than him, but Fai was not some untrained amateur. The way the spell twisted away from him felt almost personal, as if Ashura had specifically drawn it to rebuff all of _ his _ efforts to remove it.

In the absence of finesse, he would happily settle for removal by brute force. Fai hit the spell with all of his considerable power.

The backlash slammed him into the floor.

He fought for consciousness, pulling his form back into the shape that mimicked the surface dwellers. Exhaustion clouded his thoughts - too much power spent, too little water in the air to let him recharge. One hand spilled into the open water of the deep harbor.

He breathed deeply, and his heart calmed. The water coursing up his skin centered him and poured energy back into his reserves. For the first time in the last twenty-four hours, he felt close to fully charged.

But his body was so tired.

He lowered his head to the deck, letting his hand drift in the gentle currents. With several hours of ‘night’ left to go and Kurogane in his sleeping quarters in the higher levels of the central habitat, surely there was no harm in him sleeping. What else was he going to do? He couldn’t leave - intentionally or not, Ashura’s spell had seen to that. He would have to wait until they came back for him, with or without his brother, so why not sleep. Who would know? 

Technically, no person on the Ika would _ know,_ although whether or not they cared was outside Fai’s knowledge. The alarms, however - which were expertly designed by Fathom Exploration’s president to make sure that her employees didn’t do dumb things that shortened their life expectancy - _ knew, _and they went off like anything.

* * *

Something was grabbing him, yanking at him, dragging him back from the water. He twisted, trying to lash out with his tail. One foot collided with something solid, but he lacked the practice of fighting with two limbs that he needed to make the kick effective. With his tail, he could have broken bones. With his foot, he inspired a bitten-off curse and a growled, “Cut it out.”

“Let me go.” Had his mind not been working on pure instinct, he would have thought up some clever diversion. His body and mind, however, could think of little besides getting back to the water.

“So you can drown yourself?” The words had an odd lilt to them, like Kurogane was making a joke that he just didn’t get.

“As if I....” Fai’s brain crashed back to awareness of his surroundings, and he cut himself off. “I wasn’t going to drown myself.”

Because the idea of drowning himself was no longer as ludicrous as it should have been. Not only was he in the wrong place, but he was trapped here. Useless and vulnerable. He felt his lips rising, wanting to bare fangs that he didn’t have in the face of the threat. He clamped his emotions down. The threat of discovery would become all the more real if Kurogane perceived him as dangerous, as something worth investigating. 

“You fell asleep with an arm in the water.”

“Now, I know I’m just the medic and so probably don’t know a great deal about this, but I swear that we don’t breathe through our hands.” He aimed for bright and cheerful. By the look on Kurogane’s face, he’d landed on something between sarcastic and sassy.

“Because falling in is completely impossible.”

“I don’t move that much when I sleep.”

“I know.”

“Clearly, as I didn’t fall in.”

“No, I....” Kurogane drew back slightly, eyebrows drawing together. For a moment, he simply studied Fai with a piercing gaze. “I was more worried about that.” He pointed one arm past Fai and into the dark waters of the deep harbor. A wide black band wrapped around his wrist over the tattoos that marked Fai’s enchantment. The edge of the band lit with a brilliant light. It pierced through the water to highlight a sinuous curve of scales.

The creature below the water rolled slowly, exposing first dark eyes that reflected pin pricks of the light and then a mouth full of jagged teeth that seemed to be too densely populated to close properly, because the teeth snaggled out in all directions. A mouth meant for rending. The black eyes focused on them beyond the barrier of the water. This creature had never hunted near the surface or in air, but it recognized food and easy prey when it saw it and simultaneously failed to recognize the danger it would put itself into.

Tattered fins that bespoke a lifetime of fighting for survival in the austere deeps rippled along the length of its body. The motions drove a slow turn past them and showed off the decided lack of bioluminescence and even darker scales than the rare fish that darted past it. With the exception of the bright eyes, the scales seemed to absorb the light of the flashlight and flood lamps alike.

“Shadowfang,” Fai hissed, ignoring the puzzled look Kurogane turned on him. “Back up, back up.”

An ambush hunter, the shadowfang pursued prey many times its size. The myriad of needle-like teeth delivered a fast acting paralysis agent that immobilized its prey and allowed it to feed at leisure over the course of many months. Unlike many of the deep races that ate little but constantly, the shadowfang had taken a different approach to surviving in its sparse habitat.

Legend amongst the older members of the deep societies suggested that the shadowfang had evolved from a gigantic species worshipped by the Paareyans before the Bloom. That deep, the ancestor species had been nigh-on indestructible even as the Bloom poisoned the shallows. But the decimation of the shallower ecosystem had catastrophic fall-out effects on both the surface and deep ecosystems. But the shadowfangs and their presumed ancestors were built to survive.

“It can’t reach us up here.”

“It doesn’t know that.” Fai scuttled backwards, trying to get his legs to work in a combination that allowed him to move quickly and failing. He wound up dragging himself with his arms.

“I can push it back in.”

“And it can always get one fang into you and send you into a permanent coma.” It was probably a bad plan to tell Kurogane that he was guessing at how far they needed to back up before they would be past the water’s critical angle and the internal reflections would obscure them from view. It was probably an even worse plan to tell him that it was based on his experience of climbing in through the deep harbor. He backed all the way up to the wall, just to be safe.

“There are plenty of long sticks in here. We could have fresh fish for dinner tomorrow if you can figure out where the poisonous bits are.”

“Gods below, you can’t kill it!” The words fell out of his mouth. He almost screamed them in shock. No one would have thought of killing the Gods, the great ancestor race, and so the same courtesy was extended to the shadowfangs. You stayed out of their way, you protected them when they were in danger, and if they bit you and bore you down.... Fai still remembered the words whispered about his parents. _ Chosen, _society had whispered around him.

_ Blessed. _

Kurogane stared at him.

The shadowfang remained blissfully absent, although Fai probably could have used the diversion of trying to get it back into the water alive and without killing either of them.

“Fai....”

“Sorry for shouting, Kuro.” He smiled, brightly, brittly. He wasn’t sure he knew how to smile any other way. “Medic, right? I’m particularly partial to life.”

Kurogane grabbed his arm, standing and hauling Fai to his feet in one smooth motion. The action looked easy despite the fact that Fai towered over Kurogane in his native form and - thanks to pesky things like conservation of mass - still outweighed him by quite a significant factor. A slight shift in Kurogane’s stance betrayed only the briefest moment of surprise at Fai’s high density, then he was propelling Fai ahead of him and to the small lift against the wall used to access the higher levels of the central habitat.

“Something wrong, Kuro?” Fai twisted surreptitiously, surprised that Kurogane’s grip was controlling without being painful. That fine a line had to be walked intentionally.

“You have not slept since my accident in the deep harbor. I don’t know why, and right at this moment, I don’t care. If you’re worried about my injury, you shouldn’t be. I have no lingering effects. I am fine. You are not, and you are going to kill yourself.” He shoved Fai through the open door of his sleeping quarters and, when Fai made no move towards the bed, pushed Fai the rest of the way until his knees collided with the low, austere frame and he tumbled onto the mattress. “I don’t know how much sleep you need, but you are going to get it.”

“I really....” The rest of his words were muffled by a well-aimed blanket making intimate association with his face. He pulled it away, letting it crumple in his lap. “Where are you going?”

“I have a few builds that I need to take care of in engineering, and then there’s a cot in one of the panels there. Tomoyo put it in for overnight tests and it’ll work for the short term.”

“Then I’ll sleep there, Kuro. There’s no reason for me to take your bed.”

“You’ll stay here where I can monitor the door. If that opens before daylight, we’re going to have words.” Something in his tone implied that ‘words’ would be more physical than verbal, and not in the fun way.

“I’m not some truant child.”

For some inexplicable reason, this snapped response earned him a sharp smile. “No.” The door swung shut behind him, but the interlocking wheels on the inside of the door didn’t spin.

He wouldn’t have to unscrew the door to get out, at least. For the briefest of moments, he thought of running, but where would he go? The deep harbor was both an escape route and a death sentence with his gills sealed. The Ika must have some means of escape in case of a breach, whether it was a small submersible or just bottles of air. Kurogane had, presumably, used some enclosed craft to get down to the Ika, but Fai hadn’t bothered to try to locate it.

What would he do? Sail to the surface and begin a new life there? Try to find Ashura in hopes that he wouldn’t run out of air or fuel or both in the search? He wasn’t sure he could navigate from inside a cockpit - he wasn’t sure he could navigate without being in, without _ breathing,_ the water.

The exhaustion had settled into his bones. His mind churned on the possibilities without settling on anything useful. Kurogane was right - he needed to sleep. Perhaps he’d see the solution in the morning.

Laying down was pure, astonishing bliss. In the near perfect suspension of the water, his body worked to propel him, to allow him to fight and hunt, but not to support him. Lying down didn’t simulate it perfectly, but he stretched languorously, grateful for the sudden release of pressure on his joints and the relaxation that swept through his muscles.

* * *

_ “Any extra information we can get from the subsurface scans would be helpful. I know you won’t launch the sea spiders until after the storm, but the seismic collection is hard-wired and should function in the storm. Can you process the data and send us the results once comms are back up.” _

_ \- Archived memorandum, Syaoran Li (Lead Archaeologist) to Kurogane (Lead Engineer), Fathom Exploration _

_ “Kid, don’t worry. I’ll get your data.” _

_ \- Archived memorandum, Kurogane (Lead Engineer) to Syaoran Li (Lead Archaeologist), Fathom Exploration _

* * *

The room was already brightly lit when he woke. Disoriented, he struggled for a moment to free his legs from the tangle of blankets, kicking frantically. He’d pulled them over him at some point during the night. The weight had been comforting, a proxy for the constant pressure of the water that previously always surrounded him. After that, he’d barely stirred.

The inactivity woke him in a sudden panic. Every survival instinct screamed at him to get up, to move, that he was defenseless, that he was _ vulnerable_. Both of those were true, but not for the reasons that his instincts were shouting about. He rubbed a hand across the back of his neck and slowly got to his feet, instantly regretting the need to carry his entire weight.

His feet ached. That seemed immensely unfair, since his ‘feet’ hadn’t been feet a few days ago. Perhaps shoes would help with that. Maybe he could find some spares in more sizes in the other sleeping quarters. 

But Kurogane was waiting for him in the common area that took up the center of the main habitat that the sleeping quarters broke off from. “Did you sleep well?”

“Deeper than I ever have.” The best lies always have a kernel of truth.

“Good.” Kurogane slapped a bowl of what was presumably food onto the table and pointedly took a seat across from it.

After being marched to bed the night before, Fai wasn’t about to push his luck. He sank slowly into the seat, still unsure of what to do with his legs when sitting. “You made food?”

“It’s breakfast.” Kurogane pulled a bowl over to himself. “Passing out from exhaustion is against company policy, and so is passing out from starvation.”

A good policy to be sure, but he genuinely wasn’t hungry. Meals lasted him a long time, and, even with the energy lost to change his body, his metabolism still hadn’t processed the last meal he’d had. He smiled and took a polite bite of the ‘breakfast’ anyway. It wasn’t fish, but it wasn’t bad.

“Syaoran had some papers about the deep species, didn’t he?”

Fai, thankful for the mouthful of food, made a noncommittal noise.

“We’re not actively connected to the surface databanks, but the Ika keeps a mirror,” Kurogane said slowly. “You should add observation notes to his files.”

“And you, Kuro?”

“I’m still putting the finishing touches on the hammer.”

It was said as if he should know what the hammer was. “Right, of course. I’m still waking up.”

Kurogane finished off the white grains in his bowl and shoved his chair back. “Add those notes and then come down to engineering. I could use a second pair of hands.”

“Lucky for you that I’m here.”

* * *

The slowly moving water continued to waft him back and forth. With the continued motion, he couldn't return to the semi-suspended state he'd been in before. Whatever was in here with him, it seemed to pay him little mind. He'd quieted all his lights, not wanting to draw its attention, and so could see nothing, but he could still _ hear _it, could still feel the vibrations of it in the water.

Water was like a mirror, though. If he could feel its vibrations, it could certainly feel his, even if it was just from the slight motion of his fins that kept him in place. Clearly, he wasn't worth the effort of pursuing.

Given how big the thing seemed to be, he wasn't entirely surprised. He'd be little more than a wholly unsatisfying snack. Unless he collided with it, he could probably spend forever in here being ignored. At least until they ran out of oxygenated water or food or both.

So he hung near the roof, well out of the way of the continuously circling creature below him. It would ignore him, but he wondered what would happen when the gathered masses outside got the roof open. Alone, they wouldn't be worth pursuing. As a group, well.

At least it seemed to be slow, but that was possibly due to the confinement.


	3. Gods Below

"Don't look at me like that. You asked me to come down here."

"You're still not wearing shoes."

"I told you, Kuro..."

"Your preferences are not going to change the fact that I'm moving heavy machinery in here, and I don’t want to try to fix your broken foot. I'm not the medic."

"I'm sure I can patch myself up if something untoward happens." Fai said breezily. "Not the medic, indeed, What would you do without me?" His own question brought him up short. What would Kurogane have done without him? Not that Fai was particularly skilled in caring for a walker. It seemed suddenly ludicrous to have him deployed down here by himself.

"I do have rudimentary training in first aid."

He blew a breath out, making a long, high-pitched sound that surprised him. He covered it with a smile and what was almost certainly a truly indecent look up and down Kurogane's frame. Setting him back on his heels would distract him from anything odd Fai was doing. "Maybe I should injure myself so that I can see you in action."

Kurogane stared at him, deep red eyes narrowed in speculation, clearly trying to work out if Fai was serious. Finally, he just shook his head. "That's not how you whistle."

"I'll have to practice."

"Get over here."

"Are you going to show me how to whistle?"

A long silence ensued while Kurogane glared at him. "I need a second pair of hands." He held out a flat rectangular board criss-crossed by highly-reflective copper patterns. It was simultaneously lovely and utterly alien.

"That's for the hammer?"

"Control board." He meticulously closed the drawers on the workstation he was standing at and then slid it to the side on the easy-rolling caster wheels. He knelt and leveraged a panel up out of the center of the floor.

Fai tipped his head to one side and leaned against the workstation. The name Kurogane had given him - Syaoran Li - had indeed lead to a set of reports on deep sea fauna. The boy was not a biologist but seemed to be collecting the information on the deep societies and fauna in an effort to draw relationships amongst the evolution and exploration of the Paareyan before the Bloom. He dutifully added notes, not entirely certain that Kurogane wouldn’t look for them later and chide him if they were missing.

But that particular name as a search term had unlocked so much more than sketchy biological catalogues with scant information and even fewer illustrations.

Syaoran had authored dozens of reports about the deep Paareyan ruins, and Fai’s previous searches had barely scratched the surface. He’d read as fast as possible, as fast as the enchantment would allow him to comprehend their language. The reports contained so much data and still had so many gaps. He could almost taste the answer to what had happened to his brother, but it remained stubbornly out of reach.

That name also led him to a series of memos this hammer that Kurogane was wrestling with. It turned out to be little more than a large mass that struck the seafloor and was, therefore, quite aptly named.

“The timing has to be specific,” Kurogane continued, shoving the panel to the side and carefully moving handfuls of wire out of the way. “Otherwise the data is useless.”

“So you smack the seafloor, and you get to see underneath it?”

“Something like that.”

“Why did you need me? Want me to go for a swim and throw some rocks at the bottom?” Suggesting swimming made his skin hurt. He felt dessicated. He'd never been out of the water for this long and didn't want to think about how he would feel after weeks - or however long he managed to last - of being onboard the Ika. Maybe he would have to sneak into the deep harbor while Kurogane slept.

“I can’t hold the wires and put the control board in at the same time.”

“Oh.” Fai pushed himself off the workstation and picked up the control board in both hands.

“The end that’s in your right hand needs to go in first, copper side towards me.”

It took several minutes of dancing around each other before Fai found the right way to hold the board so that he wouldn’t have to stand over Kurogane to lower it in. He wound up stradling the opening with one foot practically in Kurogane’s lap, which made it easy to see the board drop in when it slotted into place and to see a series of small bulbs along the top light up. From that angle, he could pull the floor panel back into place, although moving that was surprisingly difficult. He felt a couple of twinges up the back of his legs and into his lower back in muscles that he wasn’t used to having or using. He stood for a minute with his arms braced on his legs, waiting for the spasms to subside.

Kurogane leaned head against the side of Fai’s leg and made a noise that sounded suspiciously like a snicker. “You should lift with your legs.”

“You wanted me to put that in with my feet?”

Now it was definitely progressing past a snicker and migrating towards an honest-to-goodness laugh. “You should use the muscles in your legs.”

Fai blinked down at his legs and almost said, in a tone that would have been unaccountably petulant, _ how? _ He bit the word back before he could. It seemed a stupid question to ask as someone who was supposed to have possessed legs all his life. He could feel Kurogane’s shoulder twitching against said leg in time with his soft laughter.

* * *

Unlike the deep harbor, the engineering pod hung above a rocky stretch of seafloor. An iris opened in the base of the engineering pod, just large enough to admit a cylindrical column that slowly extended across the short distance to the seafloor until the metallic footprint contacted with the rocks below. Pneumatics along the arm hissed and adjusted, their noise dampened by the inward press of the surrounding water. Electronics and programs calibrated, resetting placeholder distances, pressures, and alignments with the actual geometry of the ship and the ground, and then the hammer was raised up.

When it came down, it came down harder than the initial, tentative deployment. The metallic base hit the rocks hard enough to shatter the surface layer and send a vibration rattling through the surrounding water column and ground alike. The small schools of fish that had been endlessly circling the Ika and her bright lights darted away in confusion. The shadowfang - still there somewhere in the darkness - slunk along the perimeter of the Boiling Sands, flashing through the floodlights once before disappearing into the pressing darkness.

The hammer ratcheted up and came down again and again with several breaths between every stroke, and the rhythm continued - deep, slow, and impossibly pervasive.

* * *

_ “I just ran across some schematics for a construction on the side of a Paareyan deep outpost. I can’t quite follow how it works and could use a second opinion. It almost looks like a mago...mechanic version of our hammer - no technology required, but there’s clear instructions for applying Paareyan magic to housing for it. I have no idea why the Paareyans would have needed something like this - it’s not like they did seismic imaging.” _

_ \- Archived memorandum, Syaoran Li (_Lead Archaeologist) _to Tomoyo Daidoji (President) and Kurogane (Lead Engineer), Fathom Exploration _

_ “Mago-mechanic? That is most certainly going to need a better name.” _

_ \- Archived memorandum,Tomoyo Daidouji (President) to Syaoran Li (Lead Archaeologist), Fathom Exploration _

_ “How deep is deep, kid?” _

_ \- Archived memorandum, Kurogane (Lead Engineer) to Syaoran Li (Lead Archaeologist), Fathom Exploration _

_ “I don’t know. The schematic isn’t tied to a specific location, but there’s something about the text. It’s all conjecture from what they say, but it sounds like it’s deeper than anything they’ve ever built. There’s descriptions of other devices in this same outpost - traps and the like - that I’ve never seen in any of the descriptions of the borderlands ruins. Wherever this place is, I don’t think we’ve found it.” _

_ \- Archived memorandum, Syaoran Li (Lead Archaeologist) to Kurogane (Lead Engineer), Fathom Exploration _

* * *

The distant vibration passed through him - little more than a vertical shift in the water column, taking him up until his outstretched fingers brushed the roof and then sinking him back down again. He twisted in confusion. Whatever was causing it was not inside with him but beyond the rocks that enclosed him. It puzzled him, distracted him enough that it wasn’t until the second wave passed him that he realized that the slow circling below had changed, imperceptibly at first, and then...

A coil of muscled scales smashed into the roof where he had been scarce seconds before. The fast, rushing displacement of water had been his only warning. His own bioluminescence - an involuntary scream - scattered across shiny black scales that slipped past him in the darkness. In a world of brightly-lit predators and prey alike, the optically silent character of the beast below him was sliding straight past unnerving and into terrifying. He couldn’t _ see _it and only got the scarcest of indications as to where it was.

Another pulse passed through the cavern. The thing below him _ howled. _ The noise reverberated around the enclosed space, swamping his senses for a moment.

In the echoing silence that followed, he reached out with his magic, trying desperately to orient himself, and felt the briefest flicker of a magic that was not his own. 

Not his, but immensely familiar. The prickling of it spread up his arms, up the back of his neck, and along the spines of his fins. Only the shielding of the roof that separated him from Ashura kept the feeling bearable, but the magic was growing stronger, beyond the bounds of anything they’d ever worked, even in concert. With a sinking sensation, he realized what Ashura was about to do. Whatever efforts had previously been made to free him had clearly been tossed aside when it became obvious that he was not alone.

But freeing him would free them both. He shouted ineffectually, his light ricocheting off the surrounding stones. “No!”

The thing below him sensed the magic as well. The serpentine lengths calmed, coiling in on themselves, ready and waiting. A line of brilliant eyes opened along what he could finally identify as the head. Their ancillary illumination reflected off rows of wicked teeth that couldn’t quite be contained within the narrow, pointed jaw. 

_ Shadowfang, _his mind whispered, even though it couldn’t comprehend the shear difference in scale. A deeper voice whispered words that reconciled that difference - quiet, insidious words tinged with the hints of prayers that predated his society.

He didn’t have time to linger on it.

The prickling sensation grew into electric spikes of pain, and Ashura’s magic crashed into the closed roof. The dull, rhythmic pulsing that had so grabbed his attention faded into the background, and everything was the inexorable hum of magic burrowing through stone. Iridescent tendrils ripped into the ceiling, stitching jagged lines across the expanse above his head.

The world was full of the screaming, rending sound of the roof being pulled back to expose the cavern within. A pinprick of light at the center flickered and then grew. More of Ashura’s magic crowded in against this small defect, worrying at it.

He shoved himself against the other side of the opening and pressed his hand through, heedless of the magic that scalded his skin and the flash-boiled water coursing upwards around it. His tail lashed. His strength would do little against whatever held these doors closed, but he needed to feel like he was doing something, anything.

When the gap widened enough to admit him, he shot through it, trying to get his tail and his fins through as fast as possible to minimize the damage. Outside, without the magic and the creature reverberating around the echo chamber that he had been trapped in, the vibration was more evident. It set his teeth on edge. He wanted to claw at whatever was causing it, to tear it down until it ceased its endless noise.

He had to ignore it. He had to warn them, to tell them to stop before...

Within the enclosed space, the creature didn’t have much of a run up. But with Ashura’s magic weakening the structure, it didn’t need it. 

The beast was among them before he could get the first word out. The slow rain of debris that followed served only to confuse an already muddied battlefield. Through the wheeling lights of his comrades, he could make out blocks of rock skittering off the sides of the thing.

It didn’t seem to notice.

But the whisper of vibration got its attention. The narrow head swung to face the direction it came from, but only for a second. It had been sleeping there for who knew how long, and it was too hungry to ignore such an easily delivered meal.

How long could they distract it? Surely not forever. Surely it would only be moments until the most easily surprised and slowest to run were devoured and the creature would turn its attention to the source of that horribly inorganic vibration. It was not a single animal making those sounds - it could not be anything so easily ignored. No, it had to be a machine, manned by an unknown number of crew.

Horrific as it was, the beast was busy. No doubt it would outpace him in a fair race, but he had a head start. He could warn them and possibly stop them before it found them.

He could almost see his brother’s outrage and protest that he should get himself to safety.

But his brother was not with the unfortunate throngs below him, and he could do little more than pray that - wherever he was - he stayed safe.

* * *

Fai paced irritably around the deep harbor. It was not the same as the long swirling loops he would have used in his true form - too much effort needed to be put in to keep him moving, and his feet made obnoxious sounds on the decking whenever he stepped - but it was better than standing still.

Around him, the impact of the hammer continued to vibrate the entire station. It was worse up top. Although farther away from the sound itself, the endless motion of extension and retraction was causing the upper levels to sway. It should have been imperceptible. To someone who’s entire suite of navigational organs were designed to pick up imperceptible changes, it was incredibly disorienting.

He paused on the far side of the deep harbor, where the glass windows stretched from floor to ceiling, and pressed his face against them. In the air, the motion of the hammer was irritating. He’d been on edge since it started and was stubbornly avoiding the only real crew of the Ika for fear that he would voice his opinions of Kurogane’s machine without remembering that he wasn’t supposed to be sensitive to things like this. He could only imagine what it must be like in the water.

Fai cupped his hands around his face to shield against the internal light. In the spill of the flood lights outside, he didn’t see any sign of the myriad of fish that typically hugged the Ika’s feet.

He didn’t blame them. He’d leave if he could.

The soft dunes of sediment beyond the reach of the lights were similarly deserted no matter how much he squinted, and he was on the verge of turning away when a faint burst of light caught his eye. Bioluminescence was one thing - common and almost unavoidable at these depths - but the lights became gibberish on anything else. That had been a word, he was almost certain of it, and there had been something achingly familiar about the way they spoke.

The nearest terminal was halfway around the harbor from where he stood. He ran - or did something like it - and yanked the screen out, pawing through menus until he found the buttons that would turn off the outside lights.

The person was closer by the time that he made it back to the windows and infinitely more visible once he’d shielded his eyes from the inside lights.

“Fai.” The name fell from his lips like a prayer, even though it was now somehow odd to hear it directed at someone other than him.

Free. Alive. Safe. He hadn’t done anything to ensure his brother’s freedom, and yet here he was. The fist that had been clenched around his heart for the last several days loosened its hold. Somewhere in the back of his brain, he realized that his brother was screaming at him, face a mask of horror. It took too many excruciatingly long minutes before his mind fully processed the words.

“GET OUT!”

“What?” The word was of sound, not light, because he couldn’t speak any other way, but he would get his answer regardless.

Something collided with the upper levels of the Ika. The entire central structure tilted until water poured over one edge of the deep harbor, soaking the floor at his feet. Klaxons blared from every terminal, wanting to ensure that no one missed the failures of multiple subsystems across the ship. The lights dropped from their customary bright day lighting to a deep angry red.

Fai turned and ran across the bucking deck, trying to keep his feet underneath him and his legs moving in concert. He reached the nearest terminal again on sheer luck and slammed the exterior lights on.

Another collision, and this one was accompanied by the shrieking sound of tearing metal. A disconcertingly calm computerized voice began to announce that they’d lost the upper living quarters. Gods below, where had Kurogane gone? Was he still in engineering?

He could hear the sound of water rushing into the compromised compartments above. Surely the surface dwellers planned for emergencies like this? His kinfolk would never venture on land without a backup plan to survive in a waterless world.

The computerized voice announced that they were sealing hatches. An enormous metal door that had previously always stood open between the deep harbor and the upper levels swung shut with a resounding clang. The wheel in the center spun rapidly, and the computer continued to list off alpha-numeric names of doors that meant little to Fai, but he could feel the vibration of them shutting, isolating the flooding sections of the base.

“Level zero sealed,” the computerized voice announced.

He felt trapped - he _ was _ trapped. In the long days he’d been here, he hadn’t thought to find the oxygen tanks once he’d realized that he had nowhere to go. A stupid, and now potentially fatal, oversight. The deep harbor remained open beside him, for all the good that did him. He could choose to drown in the base or drown in the dark waters that should have been his home.

A flicker of movement beyond the windows drew his attention. For one frantic breath, he thought it was his brother, come to bear him to the depths so that he would not have to take his final breaths alone. But the thing was too large. The scales were dark and silent and slid across the glass of the deep harbor with a rasping susurration that spoke of hard edges. Fighting back against this creature would be a fool’s errand - you’d be cut to ribbons long before you managed to penetrate its armor.

The only options were retreat or sacrifice. 

Footsteps in the corridor, and the hand around his heart loosened another finger. Kurogane hadn’t been in the upper levels - wasn’t stranded and drowning beyond Fai’s reach. He turned, thoughts whirling as he tried to form a question, and was almost immediately cut off.

Kurogane collided with him, shoulder aimed for his chest below his breastbone and the rest of his mass well below Fai’s center of gravity. The blow would have felled even those practiced at the art of walking on two legs. With Fai’s limited experience, the collision floored him, tearing his precipitous balance from him and throwing him backwards.

They plunged into the dark waters of the deep harbor. As the water closed above their heads, Fai just managed to strangle down the urge to open his mouth and let the water rush in. Gods below, he had to hold his breath.

How long could he hold his breath? Returning to the water should have felt like returning home. Just dangling his arm in it had been enough to recenter him before; full submersion should have stilled the chaos in his soul, but his mind focused only on the fact that he could no longer breathe below the surface.

In the confusion of bubbles rushing from their clothes, their mouths, and something Kurogane was carrying slung over his shoulder, it took Fai a moment to right himself, feet digging into the drifted sediment below the Ika as he sought to anchor himself.

The beast above them completed its long circle and slammed into the side of the lower levels. The engineering pod came away with a scream of ruptured metal. Without the infrastructure, the hammer finally fell blissful silent, but the creature continued through to cave in the side of the deep harbor. An outburst of pressured air and inburst of water rocked both of them. The flood lights that ringed the deep harbor flickered once, twice, and went out completely.

No going back.

Kurogane raised his arm to reveal the black cuff that functioned as a flashlight and aimed it at him. Bright light flooded the dim space below the collapsed deep harbor.

Everything went blurry for a moment as Fai's eyes tried to adjust to the previous absence and then sudden presence of light. The light winked out. And flashed on again. Off and on in a stuttering pattern. The same word, over and over, but rudimentary in its form, as if the speaker knew the language but had little opportunity to practice it.

"Change," Kurogane said.

Ten minutes ago - _ five _ minutes ago - the word would have driven spikes of panic through him. He should not have been known for what he was. Given his current predicament, though, being known mattered little. If he was going to die, at least he could die as himself. With a few quick motions, he stripped off the ill-fitting clothes.

Returning to himself required so little effort. It felt like he was finally letting go of something that he'd had a stranglehold on for so long that his fingers had started to go numb. His legs annealed, the bones merging and the bone-deep ache subsiding, and he was suddenly at home in the water again, his tail swirling in the chaotic currents left in the creature's wake to keep him balanced. But his world-view twisted. With the change in size, he loomed over Kurogane and had to brace his hands against the metal sheeting above his head to keep from colliding with it. 

Over the mask that covered the lower half of Kurogane's face, Fai saw his eyes widen ever so slightly.

Then Kurogane aimed the flashlight again. "Shore." This word was uncertain, unpracticed, but the next were more confident. "Help. Me."

"Surface?" Fai asked, trying to clarify the word, and then understood. He was suited to the water - a stronger and faster swimmer - and shouldn't have been beholden to the limitations of oxygen tanks. Without his help, Kurogane would never make it to the surface alone.

"I can't...." He forced the words out, his lungs burning in a constant reminder that he would soon open his mouth to the water that could not offer him oxygen, "I won't make it."

Kurogane's brows drew together. He made a slight gesture towards his face, as if asking a question.

Even if Fai had the time to explain, he wasn't sure he could find words in his language that Kurogane would know. He touched his closed mouth and coiled over himself to try to demonstrate the lack of gills along his sides and back.

Kurogane's hand shot out, catching one of his arms and pulling him all the way around a serpentine curve until he was upright again but facing away. When Fai struggled to pull away, he linked a leg around the point where skin transitioned to scales - a gesture that would have done little if Fai had been properly breathing. With his fading strength, it nearly immobilized him. The arm that Kurogane wrapped around his forehead and used to crane Fai's head back did immobilize him. The weak, ineffectual spasms of his tail did little more than kick up a cloud of sediment around them.

Something was crammed over Fai's face, covering his nose and mouth, biting into his cheeks, and wrapping tightly around the back of his skull. Lights scattered off the sediment around him - he realized that Kurogane was trying to talk to him, but he couldn't see the flashlight clearly and couldn't think past the desperate need for air.

His brother was alive. He didn't want to die.

Reflexes finally took over, and he breathed. Air hit his lungs, not water. He gasped desperately, hauling in lungfuls of the stale stuff, and his mental capacity returned with it.

Kurogane hung a few inches from him, his mask gone and his lips pressed tightly together. "Shore," he signaled again. "Help me."

Lifting Kurogane was little harder than lifting the prey he typically hunted. After having been dwarfed by him for several days, his perspective was twisted out of true and he half expected to struggle to swim with him. But it was easy, if a bit awkward. 

At least, it was easy at first. Then the water below shifted at the passage of something massive. Rising was easy. He could adjust his buoyancy, after all. Rising quickly required effort, and the air coming from the oxygen tank seemed less and less satisfying. He dug his fins in the water, propelling them upward. Surely the creature wouldn’t bother with them, but he didn’t want to count on it. Behavior driven by anger wasn’t nearly as logical as that driven by hunger, and the thing was clearly angry.

But fear and adrenaline could only drive him so far. His upward progress inexorably slowed.

Then another arm joined his around Kurogane, grasping his elbow with a firm grip. A face that mirrored his own swam out of the darkness. "Where are we going?"

"Up."

* * *

The surface station wasn’t truly at the surface. A series of tiered rings sat well below the water level, below the wave base that would continuously buffet and shift the station. Enormous pontoons encircled the uppermost ring, their buoyancy counterbalancing the weight of structure below. Like the Ika, some of the chambers and corridors were glass while others were matte metal sheeting. Floodlights mounted on the outside curves pierced the surrounding darkness.

As they rose, first the lights and then a curved glass wall melted out of the darkness. He hadn’t bothered to study the blueprints of the surface station. They hung suspended for a moment in front of the wall of glass, indecisive. He knew they needed to get inside and suspected that the station would have a harbor like the Ika had, he just didn’t know where to find it.

Kurogane’s body was limp between them. He pressed a hand to the glass and finally focused beyond it.

Two figures stood in the hallway, staring at him. Separated by both the thick glass and the water, he had no way to speak to them. But Kurogane had known enough of his language to communicate. 

“Help,” he called, and then again, louder and brighter to drown out the floodlights. “Help!”

One of the women turned and ran. The other dropped a bag that she’d had slung over her shoulder and fished through it frantically. As she searched, she pointed down the corridor. 

They started to move, although Fai was unsure what she was trying to communicate. Then she surfaced from the bag with a small flat rectangle held between her hands. She fiddled with switches on the side, and an array of lights illuminated along the front. “Go. Help.” She pointed again.

Something was moving in the water, but it was mechanical, not organic. They turned to see a small pod shudder around the lower curve of the corridor. It swam awkwardly, the ballast off, only half the interior lights on, and a few holes that suggested missing equipment. Behind the glass globe that occupied the front, he saw the woman who’d run from the corridor a second ago. She wrestled with the controls, bringing the pod to an awkward halt in front of them, before reaching forward to press buttons on the front console. Lights illuminated along the bottom of the pod.

“Follow,” she said. An easy word to form, an easy command to obey.

A flat, cylindrical chamber occupied the center of the lowermost ring. The harbor was tucked below it, accessed by a long vertical column with ladders and occasional platforms around the outside.

A wide platform hung just below the surface at the edge of the harbor. Fai dragged himself onto it, pulling Kurogane behind him. When he finally breached the surface, he tore the mask from his face and took several long breaths of air that didn’t come from a dwindling oxygen supply.

Hands plunged into the water beside him, pulling Kurogane out and onto the decking. Shouting rang out, and people crowded around with carts and instruments. The ascent had taken too long, but Kurogane must have known that it would even before he’d given his oxygen tank to Fai. The surface societies surely possessed some means of reviving a drowned swimmer, the same way a fish could be returned to water, if done quickly enough. He couldn’t see through the throng of people, but he heard Kurogane take a sudden sharp breath and burst into a fit of coughing.

On the shallow platform, he rested his head on the edge of the pool. Each breath was blissful.

Until it wasn't.

The pain started along his extremities and flared inward until he was doubled over with it. He screamed, a thing of sound and light mingled together that dragged some of the attention towards him. His twin was pattering against his tail, trying to get him to look, trying to ask him what was wrong, but he couldn’t focus well enough to see what he was asking.

On the decking above, Kurogane’s coughs turned to ragged groans. A flurry of questions passed through the onlookers, unintelligible to him, but they clearly got the answer they were looking for.

Hands grasped him under his arms and pulled and wrestled until they managed to beach him on the edge of the harbor. He couldn’t scrape together enough brain cells to attempt the surface language, but that didn’t stop him from repeatedly signaling, “What’s happening?” A small, desperate part of him hoped that someone would understand.

“Oh.” The girl from the ship dropped into a crouch next to him. “Oh, do you...do you understand me?” She spoke slowly, enunciating the words so that, even if he hadn’t had the spell to aide his comprehension, he probably would have been able to follow.

He nodded, an affectation gleaned from Kurogane and one he was immensely grateful for. He wasn’t sure he could speak any more.

“Okay, good. You’re going to be okay - we’re going to make you better. There’s something...wrong...with the air in your blood. It’s because you were so deep, and you came up so fast.” Her hands were braced against the decking by his shoulder, and she almost reached to touch him before dropping her hand back to where it was. She smiled brightly instead. “But we’re going to fix it!”

The people beside him had already bundled Kurogane onto a low rolling cart and had whisked him away. Fai tried to push himself onto his arms so that he could see his brother. Was he suffering too? What would they do for him?

But the pain drove him back to the deck. He was dimly aware of a group gathering around him and a discussion that was too rapid for him to follow completely. They needed to move him, but feared what the corrugated metal of the floor would do to his scales if they dragged him. Words passed back and forth above him, and then hands were pressed against his side, rolling him until they could get their arms under his tail.

When they lifted him, his body spasmed, and he nearly knocked himself from their arms. A burst of curses were followed by more as he grabbed someone’s arm, but they didn’t drop him.

Kurogane was already in the chamber that they brought him to, laying on a low cot made of stretched fabric over a metal frame. A twin cot occupied the other side of the chamber, but it was far too short for him.

They laid him in the center of the floor instead. Gentle hands coiled his tail around to keep it clear of the entrance. He barely noticed them leave, barely noticed the round hatch swinging shut, and the wheel spinning in the center. After only a moment, weight settled gently around his body, the comfortable pressure making him feel almost like he was back below the water, and the pain waned.

“They’re bringing us back to the pressure of the Ika and then will lower it slowly.”

“To fix our blood?” Fai rolled his head to one side so that he could see the edge of Kurogane’s face.

“They explained it to you?”

“The girl with the short hair...”

“Sakura.” 

A face he should have known, if the lies that his spell was telling Kurogane were true, but a name he knew only through the records. As the pain and the adrenaline continued to lessen, shock rose in counterbalance. “You knew,” he said. It should have been a question, it should have been aimed at Kurogane, but it was more of a statement to ground himself. A statement to twist his perspective from what he thought was going on to what was actually going on.

“Your hair smells of the sea.” An oddly open wistfulness clung around the words, as if the sea was something beyond a topographic feature for Kurogane.

Did it? The scent of the sea was myriad to him. He was a part of it, and so he supposed he must smell of it. He’d altered his form, his speech, but it hadn’t occurred to him to tailor the way he smelled. Like his slightly odd appearance, the enchantment should have made his smell commonplace and explainable. “Why, in all of the depths, were you smelling my hair?”

Kurogane sat up at this, swinging his legs around and leaning his elbows on his knees so that he could level a glare at Fai. “You script yourself as my spouse and then get judgemental that _ I’m _ invading your privacy?”

“I...” Fai blinked as the conversation slid rapidly out of anything he’d expected. “I didn’t....”

“My memories tell me that we have been together for years. I know your hair smells of the sea because I presumably smelled it when you helped me up, but my memories tell me that I’ve woken up to it more times than I can count. The sea,” he paused, his jaw clenching briefly as he swallowed down something. Words? Emotions? “I would have told you. I remember that you smell of the sea, but I don’t remember ever explaining why that is important. The more I poke at it, the faster it slips away, and the fewer specifics I can remember.”

The enchantment would slot him into the most logical space. It made him the medic because it was the next most logical job to fill, if there were only going to be two of them on the station. It made him Kurogane’s partner because the station was only prepared for one person. With only one bunk fully outfitted, it put Fai in the only role that would fit. He remembered Kurogane beside him, so close that he could have just tilted his head to bring them into contact. The kiss, the worry, the closeness - gestures of habit born from a fictional relationship.

“I didn’t.” Fai reiterated. Had he known, he would have done something different with the spell. Scripted himself as an insomniac or an eccentric who slept in the med bay, anything but prying himself into someone else’s emotions. “The spell was generic. It placed me in your memories within the limitations of your world. I didn’t know, but I’m glad that you figured it out eventually.”

Kurogane breathed out a dark noise that seemed almost like a laugh, but with no humor behind it. “Tomoyo wouldn’t have let someone down there in an untailored uniform, and no matter your personal preference or the relationship between us, I would never have let you careen around down there without shoes.”

Fai stared at him, wondering if he’d misunderstood somewhere and trying to parse the change in topic.

“I didn’t ‘figure it out eventually.’ I knew that you didn’t belong - almost from the beginning - and the false memories became easier to ignore. It took me longer to place you as a Mimic. Our archives of the deep societies are anecdotal at best, but the Mimics are a popular theme.”

Mimics were always a popular theme. The ability to change form both ensnared the imagination and engendered fear. Fai stared at the ceiling for a long time before finally asking, “I’m an invading species. Why didn’t you just kill me?” 

“You’re an invading species. Why didn’t you just kill me?”

“What possible reason would I have...?”

Kurogane leveled a long gaze at him. “I don’t know,” he said pointedly. “But you had plenty of opportunities that you didn’t take. And whatever your motivation, you were desperate enough to trap yourself and to almost kill yourself by pretending to be something that you’re not.”

No actual question was voiced, but it hung between them nevertheless. Fai propped himself up onto his elbows, trying to ignore the itching sensation that was starting to spread across his rapidly desiccating skin and scales. “I didn’t know I was trapped,” he started, and then hung his head, the bioluminescence along his tail flashing in quiet consternation. After having been given the benefit of the doubt, he owed Kurogane an explanation. “My twin was trapped.”

“The one that helped us get to the surface?”

“It was a Paareyan ruin, or it was supposed to be. Something happened, and it sealed itself with him inside. We couldn’t get it open. Someone thought there was a connection between the ruins and the Boiling Sands, and we had reports of the Ika being deployed, and it just seemed too coincidental to ignore. Some people thought it was intentional, although how you could have known that he was there and when to trigger it, I don’t know. I just wanted to get the doors open and get him out and, if the key to that was on the Ika, I was the best chance to find it.” Even now, even with his brother safe a few corridors away from him, the thought of it was making him shake. 

Kurogane’s hand was on his shoulder, his thumb brushing against the arch of his collarbone. The motion had innate familiarity to it. 

“Kuro...?”

He dropped his hand and spat out a mouthful of curses. He held out his hands towards Fai, the inside of his wrists turned up in supplication. “Take it off.”

The itching tightness had reached his hands. The thin veneer of seawater had coated him for a few minutes after they’d hauled him out, but it had evaporated by now. He held up his dry hands in what he hoped would look apologetic. “I need water to work any spell.”

“That’s what you were doing in the deep harbor.” Kurogane muttered, more to himself than to Fai. “Why couldn’t you take the spell off your gills?”

“Someone else put it on me, and I,” Fai paused to scoff at his own circumstances. ”They prevented my magic from releasing it.”

“But they’re not the only one who could remove it?”

“Fai probably could....” He trailed off, the mistake already souring in his mouth. Lowering his head helped - he didn’t have to meet Kurogane’s gaze, at least - but he could do little to halt the conversation.

“Your twin?”

“It felt like I had already lost him. If I could still hear his name, then....” He trailed off, unsure how to explain, unsure if explanation would actually get him anywhere.

“I understand.”

And he did. Something about the way he held his body, something about the twist almost completely hidden in his words - he understood. He wanted to ask, but bit the questions back. They were on uneven footing currently - Kurogane might tell him because of the place his mind _ thought _ Fai occupied in his life.

“Youou.” Kurogane broke the silence between them and then, when Fai looked at him in puzzlement, added, “My name. My true name.”

“Yuui.” Because one trusting gesture deserved another in return and because of the relief that washed over him to admit, again, that he didn’t need to wear his brother’s name to keep him alive. But Kurogane hadn’t changed his name for him alone. All of the memorandums were signed with the single moniker that he had learned, but Kurogane’s other name didn’t seem to be discarded, merely secreted away for safe-keeping. He cocked his head to one side, studying Kurogane’s face. “Which should I call you by?”

“When have you ever called me by my real name? Why start now?”

“You do realize that it’s because I didn’t have time to fully read it before you woke up.”

And Kurogane laughed then, loud and sharp and the same laugh that had burst forth at Fai’s consternation about how, exactly, he was supposed to lift something with his legs. “You are terrible at this.”

“It’s not exactly my chosen profession.”

* * *

The deep was silent. This, in itself, was not horribly surprising. The deep was frequently silent. The sentient, and non-sentient, species of the shallow borderlands that used noise for communication and hunting would have been easy targets in the dark. Loud things in the deep had a tendency to quickly become dead and, therefore, silent.

He dove inexorably downwards, gravity pulling him and the weight of the water column at his backing pushing him along. He’d felt so light that close to the surface that it seemed like he would float away at any second.

The encroaching silence - normally nothing more than a byproduct of increasing depth - itched at him. The environs that should have felt so natural felt, instead, like the ocean around him was holding its collective breath. He pulled up, allowing himself to just float for several long moments. Soft currents trickled through his hair and across the scaled surface of his tail, but nothing suggested an impending attack. The beast that had been trapped with him may have had the advantage of being a dark shadow in darker waters, but nothing of that size could move without displacing the water around itself. He might not be able to see it coming, but he would feel it.

Instead, he felt the scarcest of prickles dragging along his arm. He whirled towards it. Something out there was reaching for him with familiar fingers. It took a moment for him to get oriented and then he realized - it was reaching to him from Ifirge. He plunged towards it.

The attack had choked the waters surrounding Ifirge with sediment. The creature must have bellied into the seafloor more than once, kicking up clouds of the stuff until even the minimal illumination from the surface couldn’t penetrate. He reared back, trying to clear the water around his face with ineffectual hands. The dirt burned in his gills.

Worse, his bioluminescence couldn’t penetrate it. He could scream all he wanted for survivors, but it would do little good.

Not that he was holding out hope. Under that stale, overpowering scent of the ocean floor muck, the water smelled of blood.

The magic - _ Ashura’s _ magic - still prickled on his skin. He stretched his hands out, long fingers spread to catch the feeling and hone him in on the direction. It took him several tries to find the right approach. Rocky outcrops loomed out of the darkness. He collided with at least one of them before he slowed down, feeling his way around the treacherous spires until he located the small cave at the base that had nearly drifted closed in the settling, disturbed sediment.

His fingers closed around ridges and whorls. The shell itself was almost too large for him to get his hand around, but intricately carved in a way that offered him enough purchase to drag it out. Recurved lines and circles cut across the natural spiral of it. The decoration reminded him so strongly of the elegant carvings within the Ifirge ruins that he almost dropped it. He clutched it to his chest and swam up, aiming for clear water.

The spell within it burned his fingers.

In the clearer waters, with his bioluminescence playing across the opalescent surfaces, the similarities between the shell and Ifirge were inescapable. He ran his fingers over them, wondering where Ashura had found such a relic and, then, what use he would have for it.

The spell was easily released, and the shell flared with a soft light before small spots along the curve began to brighten in a rhythmic pattern.

He hadn’t noticed the pattern of divots amongst the intricate carving. It was smaller - it would have to be - but unmistakable. Ashura’s light in miniature, playing out a message he would not get to deliver.

* * *

The sound of the door unbolting woke him. He wasn’t sure when he’d fallen asleep or how long he’d been out, but the air around him felt lighter even as his body felt immensely heavy. Raising himself upright took more effort than he expected. His tail was coiled under and around him. He frowned at it before deciding that sorting it out was more effort than it was worth and laid back on the deck.

“You’ve been at ambient pressure for the better part of four hours now. Tomoyo‘s satisfied that you’re not going to suddenly collapse on us, so up you get.”

If he tipped his head to one side, he could just make out the tall, angular woman with short, asymmetric dark hair. She’d been at the harbor, too - one of the people yelling instructions on what to do with them. Not Tomoyo, then, but he’d come across so many names in the files that he was unlikely to come up with a reasonable match.

On the bench above him, Kurogane sat up with a groan and waved her off.

“We retrieved the data packages by the way.” She leaned against the doorframe. “Recovery protocol for the storage drives activated as soon as the Ika lost power. Good job getting the hammer working ahead of schedule or we might be empty-handed. Funny, isn’t it? We all thought you wouldn’t be able to get that set up without an extra pair of hands.”

“Lucky that I had an extra pair of hands after all.”

“It is, isn’t it? I told you that you’d be better off with company.”

“If I may offer a counter point, I do believe that activating the hammer is what drew the attack, so perhaps my assistance....” Fai trailed off, the remaining sentence dying in his mouth at the expression on Kurogane’s face. He’d seen it a couple of times before, when Kurogane had said something that, in retrospect, was a blatant reference to his anomalous presence on the Ika. Not anger, but a mix of resignation and disappointment.

As if he’d wanted Fai to be honest. As if Fai skirting the subject indicated a lack of trust in Kurogane’s intentions. Gods below, he’d opened the door for Fai so many times, and continued to hold it open even when Fai didn’t walk through it.

Fai opened his mouth, the accusatory words, _ you cannot honestly be happy that I was there, _building behind his teeth. But the enchantment was still clouding Kurogane’s emotions, and he wouldn’t get a trustworthy answer until he could remove it.

Kurogane was watching him, red eyes narrowed. When he finally moved, he did so suddenly, rising to his feet in a single fast motion.

Fai hauled himself up on the edge of the cot. “Where are you going?”

“_We _ are going to the harbor.”

“How exactly are you going to manage that? You can’t carry me by yourself.”

Kurogane left, calling over his shoulder as he went, “I’m going to put you in a wheelbarrow.”

He pulled himself farther up the bench and tried to crane his head around far enough to see out the door. “What’s a wheelbarrow? Kuro...?” The corridor outside was too narrow, and he couldn’t see around the corner, but he strongly suspected that Kurogane was laughing.

The thing that came back in was a low trough mounted on a wheel and two legs. Fai eyed it uncertainly, wondering if he’d be able to fit in it. The Ika had been much more comfortable when he’d been comparably sized to the surface dwellers. 

The surface dwellers stopped growing at some point - they had to or they’d risk collapse under their own weight without the water to counterbalance them - and their structures reflected this. Members of the deep societies did not subscribe to the same limitations. As long as they lived, they grew. Ashura dwarfed them partially because of his species and partially because of his age. None of them knew how old Ashura actually was - marking time was difficult in the darkness of the deeps. Fai didn’t know how old he was, to be honest. They were simply bigger or smaller, older or younger.

He and his brother were old; Ashura was older. The rest of the societies viewed them as aberrations - organisms who had outlived the normal expectations for survival.

As he heaved himself over the lip of the wheelbarrow, Fai glanced at Kurogane, wondering how age presented in the surface dwellers, wondering - not for the first time - at the disadvantage he was at. Kurogane knew far more about the deep than he did about the surface.

He tumbled gracelessly into the wheelbarrow and struggled to right himself. His tail spilled over the edge until he kicked and lashed and managed to get himself mostly contained. Mostly, only because his flutes still hung over the edge, but they were nowhere near the floor. Then the entire rig tilted and threatened spill him back onto the floor. He clung to the sides for a moment until it started to roll smoothly forward and then tipped his head back to glare at Kurogane. “What now?”

“Now we go to the harbor.”

* * *

_ “With this, we are quit of it. You are quit of it. I feared that I would be forced to pass this legacy to you, feared that I would live to the end of my life like my predecessor before me without fulfilling our destiny. I never wanted that for you. _

_ I suppose you cannot feel it - the currents rising from the depths, the shuddering, heaving mass of disturbed seafloor and ocean alike. Neither of you is bound to them yet, and now neither of you will ever be bound to them. You will never feel them sheltering in your mind, sleeping and waiting for their world to live again. But the deep is finally recovered, and they are stirring. _

_ Their minds shudder, trying to throw off the shackles of the sleep that has imprisoned them for so long. Our ancestors saved them, but they could not reawaken until their keystone rose. What our ancestors preserved in Ifirge was more than just one of the Gods - it is the soul at the center of all the others, the one they all call back to. Had the keystone fallen in the Bloom, the Gods would have perished. _

_ But our ancestors’ enchantments drew this greatest of Gods’ attention, trapped it, and dragged it into an unwilling sleep. The keystone raged, but once that presence slumbered, the others followed, sinking slowly to the depths of the ocean. _

_ Now, they _ want _ to wake. Our oceans are teeming with life again; the world is closer to the world they left. But they cannot do it on their own. _

_ Our ancestors stayed to protect them. The deep societies have always existed to wait and watch and, when the time is right, release them. A trust, passed amongst the ruling hands and barred from everyone else. The Gods are too powerful, and we are too susceptible to the promises that power holds. _

_ Waking the keystone should have taken years. The enchantments have faded in these teeming seas, but the keystone slumbered on. The structures at Ifirge are set to pull it back to life - a steady beat, a vibration to mimic the Gods’ calls to battle that would shake its bones until it cast off the last vestiges of sleep and pursued the challenger. It should have taken years, but I do not have that kind of time to wait. _

_ The others that do not understand the true purpose for the deep societies call for war, and I grow weary of this world. I never wanted to leave either of you with this charge, and I could not bear to see you perish in a war that we cannot win. The surface outnumbers us, and we are ill-suited to fight on their territory. We have fulfilled our role, and I will not allow us to kill the children of our ancestors because we have forgotten why our society exists in the first place. _

_ I never intended to trap you in there with it. The exploration of Ifirge was only intended to bring life to it, to fill the water with heartbeats until the keystone could no longer ignore its hunger. _

_ But your imprisonment has brought them all here. With the sheer density of life in Ifirge, the keystone is waking, and it hungers. I feel certain that we will not survive the breach. You have seen it, I am sure, and I hope that you can hide yourself. Your brother is on the Boiling Sands. I sent him as far as I possibly could. Find him and go. _

_ Leave the deep realms. The Gods are awakening, and we no longer belong. Let them have their world.” _

_ \- Transcribed message, Ashura, Lord of the Deep _

* * *

The harbor was empty - not only the decking that surrounded it and all of the workstations, but also the platform that hung just below the surface of the water.

“Where is he?” Fai threw himself from the wheelbarrow, heaving up and over the side into something that approximated a dive into the dusky waters below. His tail slapped painfully against the lip of the harbor as he went. He didn’t notice.

A myriad of bubbles spiraled up around him, but they cleared on empty water. Even with his pupils dilated as far as they could go, he couldn’t find his brother’s shape. Light flared along his tail, up his sides, and across his face as he shouted for him.

Kurogane plunged into the water next to him, causing another cascade of bubbles that temporarily blocked his vision. When it cleared, Kurogane aimed the wrist-mounted flashlight at him. “Surface.” He jabbed a finger upwards, as if he wanted to be sure the message was clear.

The sharp pain in his chest suggested that he should probably listen. Air was still a necessity, and would be until his brother got back and could take Ashura’s spell off of him. He clawed his way back onto the underwater platform, taking a deep breath the minute that his head cleared the water.

Kurogane crouched beside him in the shallow water. “Sakura said that he went back down. She didn’t catch all of it, but he said something about looking for life.”

Life? More of the creature that had attacked the Ika? Fai leaned out over the abyss only to be pulled back by a firm grip around his upper arm.

Kurogane shook him gently, dragging his attention away from the deep, dark water. “And that he was coming back up. You have to wait.”

Of course he had to wait. What was he going to do, follow his brother into the water? The ship almost certainly didn’t have transport that could get him down there fast enough and definitely didn’t have the oxygen tanks that would sustain him for long once he was down there. The ocean was a big place. He could cast around for years looking for his brother.

He leaned away from the abyss, a silent acknowledgement of the sense in Kurogane’s words. Water poured from his hair, and he raised his hands to brush it aside. His fingers left rivulets of water trickling down the sides of his scalp.

“Let me see.” He held out his hands to Kurogane, grimacing when the dark tattoos around Kurogane’s wrists came into contact with his fingers. Gods below, the spell was a slap-dash thing. He should have put it together with more care. He should have taken a moment to breathe and collect himself before plunging ahead with Ashura’s plan to infiltrate the Ika. He shook the thoughts away. The goal now was damage control.

A deep blue light suffused the dark markings, lighting them from within. The glow flickered haphazardly, a flame struggling to take hold, and then brightened. The tattoos boiled off of Kurogane’s skin. The ink turned to rivers of azure water and poured back onto Fai’s fingers before dripping into the sea.

Each droplet hissed on impact. The internal flames darkened from iridescent blue until they looked like nothing more than the seawater surrounding them.

When the last one came away, Fai dropped Kurogane’s hands, shaking his own hands to clear the water and the spell alike and shaking his head to clear the scents of sulfur, salt, and steam.

Kurogane stared at him. “You’re still in my memories.”

“It will...” Fai started and then he faltered and stopped. His language, albeit an auditory version, had been hardwired into the spell. He hadn’t trusted his skills in the surface language to carry his bluffs. He still understood Kurogane - the spell on him was intact - but Kurogane could no longer understand him. Immersion, however, was a powerful thing. His comprehension was decent before, but his speaking had been abysmal. Now, well, he was still nowhere near fluent, but he could probably make himself understood. “Some...time.”

“How long?”

He didn’t think too hard about it, letting the word surface and hoping it was the one he meant to use. “Hours?” Explaining more, detailing how Kurogane’s brain needed the time to reset, to unravel the false strands that were currently strung through his memories, was beyond his capabilities. Acidic words burned on his tongue. He needed to say them, even if it meant reverting to his own language. “You’re stuck with me for a little bit longer.”

“What?” Kurogane’s head swung around, the last sentence with its garbled words that he couldn’t understand clearly taking him by surprise. He frowned for a long moment before finally nodding his head. “The spell was translating.”

“Yes.”

“You can understand me?”

“Your spell was not....” Fai regurgitated the word the Kurogane had used. “Translating for me.”

“You speak our language?”

“Not well.”

“That places us on even footing.”

Fai snorted, the affectation feeling odd and yet he enjoyed the emotion that the sound could carry. “Yes.”

Something broke the surface of the water behind them and then submerged again. He could make out the familiar shape of his twin skimming along just below the surface of the water, a spiral shell clutched against his chest. Their eyes locked, and he felt a pit open in the bottom of his stomach. 

Sakura had translated the word as life, but he could guess at what had really been said. They used the same word, after all, in his language, because the deep was a dangerous place. Because life was a continuous struggle, and finding life meant finding those who had failed to succumb to the myriad of dangerous.

His twin shook his head.

No life. Or, more accurately, no survivors.

* * *

“You can remove it?”

Fingers brushed across his back, tracing the arched black lines that obscured his gills. “Yes. He only warded it against you.” His twin paused for a second, and then pulled his hand away. “Do you want me to?”

“Why would I want to keep it?”

“Where are we going to go?” His twin shot back.

“I.... I don’t know.”

His twin laid back in the water, submerging himself and stretching out along the shallow platform. After a long moment of silence, he said, “Why can’t we stay here?”

“You can’t stay here.”

“We could easily duplicate Ashura’s spell. You have proven that we can survive on legs. We could see the surface and the borderlands. These people are explorers, and we can walk in both worlds - think of where we could go and what we could find!”

“Mimicking them is exhausting and painful.”

“Because you were trapped. With the spells under our own control, we could come and go as we please.”

“I don’t know if they would...”

“We should ask.” His twin cut him off. “All they can do is say no, and we will be in no different position than we are now.”

No amount of staring could conjure a reasonable argument. After a long moment, he waved a hand in acquiescence and plunged himself under the water.

Returning to a legged form was easier than it had been the first time. His body knew the form this time. He wasn’t trying to force it into an unknown framework. The process still hurt - it always did - but the pain was duller and more manageable. When the scream finally escaped from between clenched teeth, it was a protest instead of a mindless wail and was easily muffled by the water above him.

He heaved himself out of the water and almost landed on a pile of neatly folded clothes perched on the edge of the harbor. Since he was naked - a state that was likely to be frowned upon by the surface dwellers that inhabited the station - and the clothes seemed unclaimed, he pulled them on without comment. They fit remarkably well, making it immensely clear how poorly Kurogane’s spare uniforms had fit.

“Oh good. I had to guess based on Kurogane’s reports.” The woman from the hallway earlier, the one who had signaled to them while Sakura ran, was standing in the doorway. She tucked a long wave of dark hair behind one ear and a clipboard under one arm

“Reports?”

“Did you know that the external data banks - the ones that come home in the event of an emergency - cannot be accessed from within the Ika? You can write data to them, but you cannot retrieve that data until the units are returned here.”

“No.” 

“We also have a team of mental health specialists. In austere environments, especially on solo assignments, they recommend recording of any abnormalities. It allows us to trace the onset of problems and help advise treatment in the event of a compromised team member.”

“Like me?”

She made a soft noise of assent but didn’t elaborate. Instead, she turned and headed for an opening on the far side of the harbor’s deck. 

After a look back at his twin, he trailed after her, tugging the clothes straight as he went. Based on the reports, she had found him suitable clothes that she had no reason to believe he would ever use. But the clothes.... Something itched at the back of his mind, something that Kurogane had said. “Tomoyo?”

She smiled over her shoulder at him. “It’s nice to actually meet you.”

Four turns and three rooms that appeared to move on their own later, and he was unsure that he could find his way back to the harbor. The Ika seemed practically minuscule in comparison. “Where we go?” It didn’t sound right in his ears, but he couldn’t remember how to form the sentence properly.

“It’s a big station and there are a lot of people. I would hate for you to get lost.”

Fai stared at her, wondering if the vaguely menacing tone was intentional or just an error in how he was processing the language.

“It is not quite as big as the ocean, of course, but I do think we’d be just as likely to see you again if I let you loose here or if you returned to the ocean.”

That statement took even longer to parse, and he was unsure how deeply to read into it. The corridor curved slowly around the outside of the station until they came to an abrupt dead end, and he was saved from trying to formulate a response. The end of the corridor ballooned out into a glass observation globe with an assortment of mismatched chairs and tables. Kurogane was sprawled in one of the chairs, eyebrows furrowed and distant gaze locked on the water beyond.

“Look who I found.” She held her hand out, gesturing Fai to a chair as if she was little more than a guide instead of, as near as Fai could tell, the leader of the entire station.

“What did she tell you?”

“Nothing that wasn’t important for him to hear.”

“Anything intelligible?”

“Oh, Kurogane, where would the fun be if I did not let you figure it out for yourselves?” She smiled brightly at them and turned to follow the corridor back the way they had come.

Kurogane sat back farther in the chair and folded his arms across his chest, watching her go. “What did she say?”

Parroting the words back was easy. “That she would hate for me to get lost.”

Kurogane let out an unreadable snort. His gaze slowly dropped from Tomoyo’s retreating back to fix fully on Fai. “Can your twin remove the spell?”

“Yes.”

“Are you leaving then?” No assumption existed in the words. It was offered as a straightforward question with two equally available options. Kurogane was leaving the choice in his hands. 

The least he could do was answer honestly. He sank into one of the chairs opposite. “I don’t know.”

A shift happened then, a minute adjustment in the way Kurogane was sprawled in the chair. His gaze, impossibly sharp a moment before, slid away until he was staring back towards the surrounding ocean but seeming not to focus on any of it. “The borderlands are cruel and callous. The people there are the fringe of both societies, pushed out as soon as the Bloom faded. Some of our contacts have carved out an existence, but they do not live well. But Tomoyo‘s already making plans to rebuild the Ika. Deployment would be similar to the first time, and Souma’s loudly voicing her opinion that I should not go alone. She was overruled last time, but she thinks that the evidence speaks for itself.”

“Who goes?” He winced.

But his failed grammar drew Kurogane’s attention back to him. He sat up fully, leaning forward with his arms on his knees. “Can you put a spell on me that will only do translation?”

“Now?” His hair was still wet. The clothes that he’d pulled on were partially soaked through, and he had, he realized belatedly, left a trail along the corridor. At least he’d be able to find his way back.

In response, Kurogane held out his arm.

The language barrier kept him from questioning, from protesting, but the show of trust threatened to overwhelm him. He’d rewritten Kurogane’s memories the last time that he’d done this, and no matter how easily Kurogane had shrugged the insinuations of his spell, those memories had still existed and had still impinged on his emotions. The fact that Kurogane was willingly putting himself in the position to be enchanted again was hard to believe.

“Ear is better.” Fai reached out and pressed his thumb to the skin just behind Kurogane’s ear. A small drop of water peeled from his hand, glowed brightly but briefly, and then sunk into Kurogane’s skin.

“In a perfect world, I’d have someone with experience down there.”

“There isn’t...,” Fai started, so grateful to be able to switch back to his own language that he plowed into the sentence without fully thinking through what Kurogane had said. The words that he’d bitten back earlier spilled out. “You cannot honestly be happy that I was there.”

“Because we would never have activated the hammer without you? Because I would have had to wait for the rest of the crew before using it, and they would have perished alongside me? Because even if I had managed to rework the controls myself, even if I hadn’t put them in danger, I would have perished so deep that they never would have found my body? No matter how you cut it, no matter what role you were supposed to be playing or how badly you try to cast yourself as a villain, that story ends better with you in it.”

“You want to believe that because of the after effects of the spell.”

“Stop being an idiot.”

Putting the spell on Kurogane had pulled him closer, the two of them leaning together to close the distance over the intervening table. Kurogane closed it farther, bringing himself within a finger’s breadth of Fai and hovering there, just as he had on the Ika. But this pause held a question instead of confusion, a request for permission instead of a frantic scramble to halt an impulsive action.

This pause held curiosity, a willingness to try and fail, if need be. He was no longer trapped, no longer bound to a location even if everything went sideways. The Ika had been terrifying for a myriad of reasons, but Kurogane had not been one of them. It was hard to view their interactions without the filter of his twin’s entrapment or his imminent discovery, but Kurogane had known practically from the beginning and had tried to help as best he could. His behavior had been despite Fai’s true nature, and Fai couldn’t help but wonder how it would be with all pretexts between them set aside. The pause held curiosity from Kurogane’s side, but also from his. The offer was there, waiting for him to take it.

“Stay.” Kurogane murmured. 

And Fai let himself fall forward.

* * *

The deep water was dark, but not as dark as it had been in the aftermath of Ifirge. Life flickered amongst the rocks that loomed out of the thick sediment cover of the Boiling Sands. Along with the influx of other life, the shadowfangs poured up from the abyssal deeps around the Boiling Sands. Matte black coils wrapped the legs of the Ika 2.0 just below the bright flood lights that so readily attracted prey. As the shadowfangs only left their deep nesting grounds to hunt, their presence suggested the arrival of a new player to the field.

After all, predators were only ousted by other predators. 

“God below,” he murmured, the words less of a curse and more of a prayer. If you stared to the edge of the boiling sands, to where the seafloor dropped away to the deep abyssal plains, and you watched long enough, you could see the occasional tears in the darkness. A coil here, a ragged fin there. Had they set down any closer to the edge, he would have thought twice about going into the water. As it was, he watched through the curved glass, trying to parse their hunting patterns and those of the shadowfangs. If he watched long enough, he might be able to set safe exploration times for the surface dwellers who would eventually join them.

“I thought we talked about this.” The voice came from behind him, but didn’t particularly startle him. He’d been expecting it for the better part of an hour.

“Talked about what?”

“It’s the middle of the night.”

“Perhaps you are dreaming, Kuro. Is scolding me for my sleeping habits so entertaining that you bring it into your dreams?”

“Nice try.” Kurogane yawned and leaned against the wall, letting his head fall against the glass. “How long have you been out here?”

“An hour or so.”

“Try to come to bed at some point.”

He did need the sleep, even if it wasn’t as much as Kurogane or the other surface dwellers needed. “Are you lecturing your medic on proper self care?”

It had taken weeks for him to joke about their shared time on the Ika 1.0. The wicked smile and wry retorts that had met his hesitant attempts had spurred him on.

“Medic? You can’t tell my toes from my knees.”

“What, amongst the land and all the waters around, could you possibly need with so many joints? And why make them so fragile?”

“If you actually wore the shoes we provided you, you wouldn’t stub your toes.”

“I told you, Kuro, I don’t wear shoes.”

Although the easy banter sounded little different, it no longer masked his true soul, but exposed and enveloped it. Statements were no longer truths through the virtue of omission, but verbal jabs made funny because Kurogane knew him for what he was. 

They entered the common area in the central column of the Ika and crossed to the bunk that had previously been Kurogane’s alone. The gentle currents creaked against the Ika’s outer hull, and sleep came easily.

**Notes for the Chapter:**

> Thank you so much for reading! Head over to the KuroFai Dreamwidth Community (kurofai.dreamwidth.org) to score and see other entries for the 2019 KuroFai Olympics


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